Vulnerability Scanning Lab with OpenVAS and Metasploitable2

This write-up documents a practical vulnerability scanning project using VirtualBox to simulate a small-scale enterprise environment with OpenVAS (Greenbone Vulnerability Management) on Kali Linux. A Kali Linux VM is configured as the OpenVAS scanner, while Metasploitable2 acts as the scan target. This lab demonstrates how to perform vulnerability detection and risk triage using an industry-standard scanning tool in a resource-constrained environment suitable for a single-laptop setup. The Kali Linux, OpenVAS and Metasploitable2 VM setups are not included in detail, as it was completed beforehand.

1. Project Infrastructure Setup
2. Vulnerability Scanning of Metasploitable2
3. Summary of Remediation Steps

Project Infrastructure Setup

• The first thing to setup is OpenVAS in Kali Linux. The installation and usage guide for OpenVAS in Kali Linux can be found in these 2 links below:
  • OpenVAS Setup
  • Perform a Vulnerability Scan With OpenVAS
• The download links for Metasploitable2 is: Metasploitable2 download link
• After the downloads for all the disc images are completed, install them in VirtualBox and allocate suitable memory and storage. Here is a guide on setting up Metasploitable in VirtualBox
• For this project, the networking mode used for all the VMs is Bridged Adapter

Vulnerability Scanning of Metasploitable2

• Power on Kali Linux and Metasploitable VMs. From the Kali Linux VM, ping the Metasploitable VM and ensure it can be reached
  
  

• List all the running containers using the following command to ensure OpenVAS is not actively running yet

  docker ps -a
  

  and run

  sudo gvm-check-setup
  

  
  

• Once you see a It seems like your GWM-23.11.0 installation is OK., OpenVAS is ready to be used without any problems

• If the error notification for ERROR: gsad service did not start appears, run

  sudo systemctl status gsad
  

  and

  sudo systemctl restart gsad
  

  to check and restart the Greenbone Security Assistant Daemon (GSAD)

• To update OpenVAS database that contains CVEs and etc., use

  sudo greenbone-feed-sync
  

• To start OpenVAS, run the command

  docker run -d -p 443:443 -p 9392:9392 --name openvas mikesplain/openvas
  

  and enter the following URL in the web browser: https://127.0.0.1:9392/login. The login username and password are both set to admin
  

• To start a scan on Metasploitable VM, navigate to the Scans tab and hover over to New Task
  

• Fill in the following details for the New Task. Input the IP address of Metasploitable VM when a window for Scan Targets appear
  

• Now start the task
  

• After a while of waiting, the scanning task is finally completed. The severity of Metasploitable is 10.0 (High) which is to be expected
  

• To view the Report created after the completed scanning, click on Scans tab and navigate to Reports
  

• By clicking on the date, the report can be viewed in detail. The vulnerabilities detected can be found in the Results tab
  
  

  
  

  

Summary of Remediation Steps

The detected vulnerabilities in order of decreasing severity and their respective remediation steps are summarised into the following table:

Vulnerability Title	Severity	Description	Suggested Remediation
rlogin Passwordless Login	10.0 (High)	Possible to gain root access without password	Disable the rlogin service and use alternatives like SSH instead.
The rexec service is running	10.0 (High)	rexec (remote execution client for an exec server) has the same kind of functionality that rsh has: you can execute shell commands on a remote computer. The main difference is that rexec authenticate by reading the username and password unencrypted from the socket.	Disable the rexec service and use alternatives like SSH instead.
Operating System (OS) End of Life (EOL) Detection	10.0 (High)	An EOL version of an OS is not receiving any security updates from the vendor. Unfixed security vulnerabilities might be leveraged by an attacker to compromise the security of this host.	Upgrade the OS on the remote host to a version which is still supported and receiving security updates by the vendor.
Possible Backdoor: Ingreslock	10.0 (High)	Attackers can exploit this issue to execute arbitrary commands in the context of the application.	A whole cleanup of the infected system is recommended.
TWiki XSS and Command Execution Vulnerabilities	10.0 (High)	%URLPARAM{}% variable is not properly sanitized which lets attackers conduct cross-site scripting attack. %SEARCH{}% variable is not properly sanitised before being used in an eval() call which lets the attackers execute perl code through eval injection attack. Successful exploitation could allow execution of arbitrary script code or commands. This could let attackers steal cookie-based authentication credentials or compromise the affected application.	Upgrade to version 4.2.4 or later.
Distributed Ruby (dRuby/DRb) Multiple RCE Vulnerabilities	10.0 (High)	By default, Distributed Ruby does not impose restrictions on allowed hosts or set the $SAFE environment variable to prevent privileged activities. If other controls are not in place, especially if the Distributed Ruby process runs with elevated privileges, an attacker could execute arbitrary system commands or Ruby scripts on the Distributed Ruby server. An attacker may need to know only the URI of the listening Distributed Ruby server to submit Ruby commands.	Administrators of environments that rely on Distributed Ruby should ensure that appropriate controls are in place. Code-level controls may include implementing taint on untrusted input, setting $SAFE levels appropriately (>=2 is recommended if untrusted hosts are allowed to submit Ruby commands, and >=3 may be appropriate), including drb/acl.rb to set ACLEntry to restrict access to trusted hosts
Apache Tomcat AJP RCE Vulnerability (Ghostcat)	9.8 (High)	It was possible to read the file "/WEB-INF/web.xml" through the AJP connector. Apache Tomcat server has a file containing vulnerability, which can be used by an attacker to read or include any files in all webapp directories on Tomcat, such as webapp configuration file or source code.	Update Apache Tomcat to version 7.0.100, 8.5.51, 9.0.31 or later. For other products using Tomcat please contact the vendor for more information on fixed versions.
vsftpd Compromised Source Packages Backdoor Vulnerability	9.8 (High)	The tainted source package contains a backdoor which opens a shell on port 6200/tcp.	The repaired package can be downloaded from the referenced vendor homepage. Please validate the package with its signature.
PHP < 5.3.13, 5.4.x < 5.4.3 Multiple Vulnerabilities - Active Check	9.8 (High)	When PHP is used in a CGI-based setup (such as Apache's mod_cgid), the php-cgi receives a processed query string parameter as command line arguments which allows command-line switches, such as -s, -d or -c to be passed to the php-cgi binary, which can be exploited to disclose source code and obtain arbitrary code execution. An example of the -s command, allowing an attacker to view the source code of index.php is: http://example.com/index.php?-s	PHP: Update to version 5.3.13, 5.4.3 or later
DistCC RCE Vulnerability (CVE-2004-2687)	9.3 (High)	DistCC 2.x, as used in XCode 1.5 and others, when not configured to restrict access to the server port, allows remote attackers to execute arbitrary commands via compilation jobs, which are executed by the server without authorization checks.	Vendor updates are available. Please see the references for more information.
PostgreSQL Default Credentials (PostgreSQL Protocol)	9.0 (High)	It was possible to login as user postgres with password "postgres".	Change the password as soon as possible.
VNC Brute Force Login	9.0 (High)	It was possible to connect to the VNC server with the password: password. This script tries to authenticate to a VNC server with the passwords set in the password preference. It will also test and report if no authentication / password is required at all. Note: Some VNC servers have a blacklisting scheme that blocks IP addresses after five unsuccessful connection attempts for a period of time. The script will abort the brute force attack if it encounters that it gets blocked. Note as well that passwords can be max. 8 characters long.	Change the password to something hard to guess or enable password protection at all.
UnrealIRCd Authentication Spoofing Vulnerability	8.1 (High)	The flaw exists due to an error in the 'm_authenticate' function in 'modules/m_sasl.c' script. Successful exploitation of this vulnerability will allows remote attackers to spoof certificate fingerprints and consequently log in as another user.	Upgrade to UnrealIRCd 3.2.10.7, or 4.0.6, or later.
UnrealIRCd Backdoor	7.5 (High)	Remote attackers can exploit this issue to execute arbitrary system commands within the context of the affected application.	Install latest version of unrealircd and check signatures of software you're installing.
Java RMI Server Insecure Default Configuration RCE Vulnerability - Active Check	7.5 (High)	The vulnerability exists because of an incorrect default configuration of the Remote Method Invocation (RMI) Server in the affected software. An unauthenticated, remote attacker could exploit the vulnerability by transmitting crafted packets to the affected software. When the packets are processed, the attacker could execute arbitrary code on the system with elevated privileges.	Disable class-loading. Please contact the vendor of the affected system for additional guidance.
FTP Brute Force Logins Reporting	7.5 (High)	It was possible to login with the following credentials : msfadmin:msfadmin postgres:postgres service:service user:user	Change the password as soon as possible.
Test HTTP dangerous methods	7.5 (High)	We could upload the following files via the PUT method at this web server: http://192.168.0.166/dav/puttest829354967.html. We could delete the following files via the DELETE method at this web server: http://192.168.0.166/dav/puttest829354967.html. Enabled PUT method: This might allow an attacker to upload and run arbitrary code on this web server. Enabled DELETE method: This might allow an attacker to delete additional files on this web server.	Use access restrictions to these dangerous HTTP methods or disable them completely.
rsh Unencrypted Cleartext Login	7.5 (High)	The rsh service is misconfigured so it is allowing connections without a password or with default root:root credentials.	Disable the rsh service and use alternatives like SSH instead.
SSL/TLS: OpenSSL CCS Man in the Middle Security Bypass Vulnerability	7.4 (High)	OpenSSL does not properly restrict processing of ChangeCipherSpec messages, which allows man-in-the-middle attackers to trigger use of a zero-length master key in certain OpenSSL-to-OpenSSL communications, and consequently hijack sessions or obtain sensitive information, via a crafted TLS handshake, aka the 'CCS Injection' vulnerability. Successfully exploiting this issue may allow attackers to obtain sensitive information by conducting a man-in-the-middle attack. This may lead to other attacks.	Updates are available.
TWiki Cross-Site Request Forgery Vulnerability (Sep 2010)	6.8 (Medium)	Attack can be done by tricking an authenticated TWiki user into visiting a static HTML page on another side, where a Javascript enabled browser will send an HTTP POST request to TWiki, which in turn will process the request as the TWiki user.	Upgrade to TWiki version 4.3.2 or later.
Multiple Vendors STARTTLS Implementation Plaintext Arbitrary Command Injection Vulnerability	6.8 (Medium)	An attacker can exploit this issue to execute arbitrary commands in the context of the user running the application. Successful exploits can allow attackers to obtain email usernames and passwords.	Updates are available.
Anonymous FTP Login Reporting	6.4 (Medium)	It was possible to login to the remote FTP service with the following anonymous account(s): anonymous:anonymous@example.com, ftp:anonymous@example.com. A host that provides an FTP service may additionally provide Anonymous FTP access as well. Under this arrangement, users do not strictly need an account on the host. Instead the user typically enters 'anonymous' or 'ftp' when prompted for username. Although users are commonly asked to send their email address as their password, little to no verification is actually performed on the supplied data. Remark: NIST don't see 'configuration issues' as software flaws so the referenced CVE has a severity of 0.0. The severity of this VT has been raised by Greenbone to still report a configuration issue on the target.	If you do not want to share files, you should disable anonymous logins.
jQuery < 1.9.0 XSS Vulnerability	6.1 (Medium)	The jQuery(strInput) function does not differentiate selectors from HTML in a reliable fashion. In vulnerable versions, jQuery determined whether the input was HTML by looking for the '<' character anywhere in the string, giving attackers more flexibility when attempting to construct a malicious payload. In fixed versions, jQuery only deems the input to be HTML if it explicitly starts with the '<' character, limiting exploitability only to attackers who can control the beginning of a string, which is far less common.	Update to version 1.9.0 or later.
TWiki < 6.1.0 XSS Vulnerability	6.1 (Medium)	bin/statistics in TWiki 6.0.2 allows XSS via the webs parameter.	Update to version 6.1.0 or later.
Samba 3.0.0 <= 3.0.25rc3 MS-RPC Remote Shell Command Execution Vulnerability - Active Check	6.0 (Medium)	Samba is prone to a vulnerability that allows attackers to execute arbitrary shell commands because the software fails to sanitize user-supplied input. Sends a crafted SMB request and checks if the target is connecting back to the scanner host. Note: For a successful detection of this flaw the scanner host needs to be able to directly receive ICMP echo requests from the target.	Updates are available. Please see the referenced vendor advisory.
TWiki CSRF Vulnerability	6.0 (Medium)	Remote authenticated user can create a specially crafted image tag that, when viewed by the target user, will update pages on the target system with the privileges of the target user via HTTP requests.	Upgrade to version 4.3.1 or later.
SSL/TLS: Deprecated SSLv2 and SSLv3 Protocol Detection	5.9 (Medium)	In addition to TLSv1.0+ the service is also providing the deprecated SSLv3 protocol and supports one or more ciphers. Those supported ciphers can be found in the 'SSL/TLS: Report Supported Cipher Suites' (OID: 1.3.6.1.4.1.25623.1.0.802067) VT. The SSLv2 and SSLv3 protocols contain known cryptographic flaws like: CVE-2014-3566: Padding Oracle On Downgraded Legacy Encryption (POODLE) and CVE-2016-0800: Decrypting RSA with Obsolete and Weakened eNcryption (DROWN)	It is recommended to disable the deprecated SSLv2 and/or SSLv3 protocols in favor of the TLSv1.2+ protocols.
SSL/TLS: Report Weak Cipher Suites	5.9 (Medium)	'Weak' cipher suites accepted by this service via the SSLv3 protocol: TLS_RSA_WITH_RC4_128_SHA. 'Weak' cipher suites accepted by this service via the TLSv1.0 protocol: TLS_RSA_WITH_RC4_128_SHA. These rules are applied for the evaluation of the cryptographic strength: RC4 is considered to be weak (CVE-2013-2566, CVE-2015-2808). Ciphers using 64 bit or less are considered to be vulnerable to brute force methods and therefore considered as weak (CVE-2015-4000). 1024 bit RSA authentication is considered to be insecure and therefore as weak. Any cipher considered to be secure for only the next 10 years is considered as medium. Any other cipher is considered as strong	The configuration of this services should be changed so that it does not accept the listed weak cipher suites anymore.
HTTP Debugging Methods (TRACE/TRACK) Enabled	5.8 (Medium)	The remote web server supports the TRACE and/or TRACK methods. TRACE and TRACK are HTTP methods which are used to debug web server connections. It has been shown that web servers supporting this methods are subject to cross-site-scripting attacks, dubbed XST for Cross-Site-Tracing, when used in conjunction with various weaknesses in browsers.	Disable the TRACE and TRACK methods in your web server configuration.
Weak Host Key Algorithm(s) (SSH)	5.3 (Medium)	The remote SSH server supports the following weak host key algorithm(s) ssh-dss : Digital Signature Algorithm (DSA) / Digital Signature Standard (DSS)	Disable the reported weak host key algorithm(s).
SSL/TLS: Server Certificate / Certificate in Chain with RSA keys less than 2048 bits	5.3 (Medium)	The remote SSL/TLS server is using the following certificate(s) with a RSA key with less than 2048 bits (public-key-size:public-key-algorithm:serial:issuer): 1024:RSA:00FAF93A4C7FB6B9CC:1.2.840.113549.1.9.1=#726F6F74407562756E74753830342D626173652E6C6F63616C646F6D61696E,CN=ubuntu804-base.localdomain,OU=Office for Complication of Otherwise Simple Affairs,O=OCOSA,L=Everywhere,ST=There is no such thing outside US,C=XX (Server certificate)	Replace the certificate with a stronger key and reissue the certificates it signed.
phpinfo() Output Reporting (HTTP)	5.3 (Medium)	Many PHP installation tutorials instruct the user to create a file called phpinfo.php or similar containing the phpinfo() statement. Such a file is often left back in the webserver directory.	Delete the listed files or restrict access to them.
Weak Key Exchange (KEX) Algorithm(s) Supported (SSH)	5.3 (Medium)	The remote SSH server supports the following weak KEX algorithm(s): diffie-hellman-group-exchange-sha1 (Using SHA-1) and diffie-hellman-group1-sha1 (Using Oakley Group 2 (a 1024-bit MODP group) and SHA-1). 1024-bit MODP group / prime KEX algorithms: Millions of HTTPS, SSH, and VPN servers all use the same prime numbers for Diffie-Hellman key exchange. Practitioners believed this was safe as long as new key exchange messages were generated for every connection. However, the first step in the number field sieve-the most efficient algorithm for breaking a Diffie-Hellman connection-is dependent only on this prime. A nation-state can break a 1024-bit prime.	Disable the reported weak KEX algorithm(s): 1024-bit MODP group / prime KEX algorithms. Alternatively use elliptic-curve Diffie-Hellmann in general, e.g. Curve 25519.
/doc directory browsable	5.0 (Medium)	The /doc directory is browsable. /doc shows the content of the /usr/doc directory and therefore it shows which programs and - important! - the version of the installed programs. Vulnerable URL: http://192.168.0.166/doc/	Use access restrictions for the /doc directory
SSL/TLS: Certificate Expired	5.0 (Medium)	This script checks expiry dates of certificates associated with SSL/TLS-enabled services on the target and reports whether any have already expired.	Replace the SSL/TLS certificate by a new one.
awiki <= 20100125 Multiple LFI Vulnerabilities - Active Check	5.0 (Medium)	awiki is prone to multiple local file include (LFI) vulnerabilities because it fails to properly sanitize user-supplied input. Vulnerable URL: http://192.168.0.166/mutillidae/index.php?page=/etc/passwd	No known solution was made available for at least one year since the disclosure of this vulnerability. Likely none will be provided anymore. General solution options are to upgrade to a newer release, disable respective features, remove the product or replace the product by another one.
Check if Mailserver answer to VRFY and EXPN requests	5.0 (Medium)	The Mailserver on this host answers to VRFY and/or EXPN requests. VRFY and EXPN ask the server for information about an address. They are inherently unusable through firewalls, gateways, mail exchangers for part-time hosts, etc.	Disable VRFY and/or EXPN on your Mailserver. For postfix add 'disable_vrfy_command=yes' in 'main.cf'. For Sendmail add the option 'O PrivacyOptions=goaway'. It is suggested that, if you really want to publish this type of information, you use a mechanism that legitimate users actually know about, such as Finger or HTTP.
SSL/TLS: Renegotiation DoS Vulnerability (CVE-2011-1473, CVE-2011-5094)	5.0 (Medium)	The flaw exists because the remote SSL/TLS service does not properly restrict client-initiated renegotiation within the SSL and TLS protocols. Note: The referenced CVEs are affecting OpenSSL and Mozilla Network Security Services (NSS) but both are in a DISPUTED state with the following rationale: It can also be argued that it is the responsibility of server deployments, not a security library, to prevent or limit renegotiation when it is inappropriate within a specific environment. The flaw might make it easier for remote attackers to cause a DoS (CPU consumption) by performing many renegotiations within a single connection.	Users should contact their vendors for specific patch information. A general solution is to remove/disable renegotiation capabilities altogether from/in the affected SSL/TLS service.
FTP Unencrypted Cleartext Login	4.8 (Medium)	The remote host is running a FTP service that allows cleartext logins over unencrypted connections. An attacker can uncover login names and passwords by sniffing traffic to the FTP service.	Enable FTPS or enforce the connection via the 'AUTH TLS' command. Please see the manual of the FTP service for more information.
Cleartext Transmission of Sensitive Information via HTTP	4.8 (Medium)	The host / application transmits sensitive information (username, passwords) in cleartext via HTTP. The following input fields were identified (URL:input name): http://192.168.0.166/dvwa/login.php:password, http://192.168.0.166/phpMyAdmin/:pma_password, http://192.168.0.166/phpMyAdmin/?D=A:pma_password, http://192.168.0.166/tikiwiki/tiki-install.php:pass, http://192.168.0.166/twiki/bin/view/TWiki/TWikiUserAuthentication:oldpassword. An attacker could use this situation to compromise or eavesdrop on the HTTP communication between the client and the server using a man-in-the-middle attack to get access to sensitive data like usernames or passwords.	Enforce the transmission of sensitive data via an encrypted SSL/TLS connection. Additionally make sure the host / application is redirecting all users to the secured SSL/TLS connection before allowing to input sensitive data into the mentioned functions.
VNC Server Unencrypted Data Transmission	4.8 (Medium)	The remote host is running a VNC server providing one or more insecure or cryptographically weak Security Type(s) not intended for use on untrusted networks. An attacker can uncover sensitive data by sniffing traffic to the VNC server.	Run the session over an encrypted channel provided by IPsec [RFC4301] or SSH [RFC4254]. Some VNC server vendors are also providing more secure Security Types within their products.
Telnet Unencrypted Cleartext Login	4.8 (Medium)	The remote host is running a Telnet service that allows cleartext logins over unencrypted connections. An attacker can uncover login names and passwords by sniffing traffic to the Telnet service.	Replace Telnet with a protocol like SSH which supports encrypted connections.
phpMyAdmin 'error.php' Cross Site Scripting Vulnerability	4.3 (Medium)	The flaw is caused by input validation errors in the 'error.php' script when processing crafted BBcode tags containing '@' characters, which could allow attackers to inject arbitrary HTML code within the error page and conduct phishing attacks.	No known solution was made available for at least one year since the disclosure of this vulnerability. Likely none will be provided anymore. General solution options are to upgrade to a newer release, disable respective features, remove the product or replace the product by another one.
jQuery < 1.6.3 XSS Vulnerability	4.3 (Medium)	Cross-site scripting (XSS) vulnerability in jQuery before 1.6.3, when using location.hash to select elements, allows remote attackers to inject arbitrary web script or HTML via a crafted tag.	Update to version 1.6.3 or later.
SSL/TLS: Deprecated TLSv1.0 and TLSv1.1 Protocol Detection	4.3 (Medium)	The TLSv1.0 and TLSv1.1 protocols contain known cryptographic flaws like: CVE-2011-3389: Browser Exploit Against SSL/TLS (BEAST). CVE-2015-0204: Factoring Attack on RSA-EXPORT Keys Padding Oracle On Downgraded Legacy Encryption (FREAK). An attacker might be able to use the known cryptographic flaws to eavesdrop the connection between clients and the service to get access to sensitive data transferred within the secured connection. Furthermore newly uncovered vulnerabilities in this protocols won't receive security updates anymore.	It is recommended to disable the deprecated TLSv1.0 and/or TLSv1.1 protocols in favor of the TLSv1.2+ protocols.
Weak Encryption Algorithm(s) Supported (SSH)	4.3 (Medium)	The remote SSH server supports the following weak client-to-server encryption algorithm(s): 3des-cbc, aes128-cbc, aes192-cbc, aes256-cbc, arcfour, arcfour128, arcfour256, blowfish-cbc, cast128-cbc, rijndael-cbc@lysator.liu.se. The 'arcfour' cipher is the Arcfour stream cipher with 128-bit keys. The Arcfour cipher is believed to be compatible with the RC4 cipher [SCHNEIER]. Arcfour (and RC4) has problems with weak keys, and should not be used anymore. The 'none' algorithm specifies that no encryption is to be done. Note that this method provides no confidentiality protection, and it is NOT RECOMMENDED to use it. A vulnerability exists in SSH messages that employ CBC mode that may allow an attacker to recover plaintext from a block of ciphertext.	Disable the reported weak encryption algorithm(s).
SSL/TLS: RSA Temporary Key Handling 'RSA_EXPORT' Downgrade Issue (FREAK)	4.3 (Medium)	This host is accepting 'RSA_EXPORT' cipher suites and is prone to a man-in-the-middle (MITM) vulnerability. 'RSA_EXPORT' cipher suites accepted by this service via the SSLv3 and TLSv1.0 protocol: TLS_DHE_RSA_EXPORT_WITH_DES40_CBC_SHA, TLS_RSA_EXPORT_WITH_DES40_CBC_SHA, TLS_RSA_EXPORT_WITH_RC2_CBC_40_MD5, TLS_RSA_EXPORT_WITH_RC4_40_MD5. Flaw is due to improper handling RSA temporary keys in a non-export RSA key exchange cipher suite. Successful exploitation will allow remote attacker to downgrade the security of a session to use 'RSA_EXPORT' cipher suites, which are significantly weaker than non-export cipher suites. This may allow a man-in-the-middle attacker to more easily break the encryption and monitor or tamper with the encrypted stream.	Remove support for 'RSA_EXPORT' cipher suites from the service. Please see the references for more resources supporting you with this task. If the service is using OpenSSL: Update to version 0.9.8zd, 1.0.0p, 1.0.1k or later.
SSL/TLS: Diffie-Hellman Key Exchange Insufficient DH Group Strength Vulnerability	4.0 (Medium)	The SSL/TLS service uses Diffie-Hellman groups with insufficient strength (key size < 2048). Server Temporary Key Size: 1024 bits. The Diffie-Hellman group are some big numbers that are used as base for the DH computations. They can be, and often are, fixed. The security of the final secret depends on the size of these parameters. It was found that 512 and 768 bits to be weak, 1024 bits to be breakable by really powerful attackers like governments.	Deploy (Ephemeral) Elliptic-Curve Diffie-Hellman (ECDHE) or use a 2048-bit or stronger Diffie-Hellman group. Please see the references for more resources supporting you with this task. For Apache Web Servers: Beginning with version 2.4.7, mod_ssl will use DH parameters which include primes with lengths of more than 1024 bits.
SSL/TLS: Certificate Signed Using A Weak Signature Algorithm	4.0 (Medium)	The remote service is using a SSL/TLS certificate in the certificate chain that has been signed using a cryptographically weak hashing algorithm. The following hashing algorithms used for signing SSL/TLS certificates are considered cryptographically weak and not secure enough for ongoing use: Secure Hash Algorithm 1 (SHA-1), Message Digest 5 (MD5), Message Digest 4 (MD4), Message Digest 2 (MD2). Beginning as late as January 2017 and as early as June 2016, browser developers such as Microsoft and Google will begin warning users when visiting web sites that use SHA-1 signed Secure Socket Layer (SSL) certificates. NOTE: The script preference allows to set one or more custom SHA-1 fingerprints of CA certificates which are trusted by this routine. The fingerprints needs to be passed comma-separated and case-insensitive: Fingerprint1 or fingerprint1, Fingerprint2	Servers that use SSL/TLS certificates signed with a weak SHA-1, MD5, MD4 or MD2 hashing algorithm will need to obtain new SHA-2 signed SSL/TLS certificates to avoid web browser SSL/TLS certificate warnings.
SSL/TLS: 'DHE_EXPORT' MITM Security Bypass Vulnerability (LogJam)	3.7 (Low)	This host is accepting 'DHE_EXPORT' cipher suites and is prone to a man-in-the-middle (MITM) vulnerability. 'DHE_EXPORT' cipher suites accepted by this service via the SSLv3 and TLSv1.0 protocol: TLS_DHE_RSA_EXPORT_WITH_DES40_CBC_SHA, TLS_DH_anon_EXPORT_WITH_DES40_CBC_SHA, TLS_DH_anon_EXPORT_WITH_RC4_40_MD5. Flaw is triggered when handling Diffie-Hellman key exchanges defined in the 'DHE_EXPORT' cipher suites. Successful exploitation will allow a man-in-the-middle attacker to downgrade the security of a TLS session to 512-bit export-grade cryptography, which is significantly weaker, allowing the attacker to more easily break the encryption and monitor or tamper with the encrypted stream.	Remove support for 'DHE_EXPORT' cipher suites from the service. Please see the references for more resources supporting you with this task. If the service is using OpenSSL: Update to version 1.0.1n, 1.0.2b or later.
SSL/TLS: SSLv3 Protocol CBC Cipher Suites Information Disclosure Vulnerability (POODLE)	3.4 (Low)	This host is prone to an information disclosure vulnerability. The flaw is due to the block cipher padding not being deterministic and not covered by the Message Authentication Code. Successful exploitation will allow a man-in-the-middle attackers gain access to the plain text data stream.	Possible Mitigations are disabling SSLv3, disabling cipher suites supporting CBC cipher modes, and enabling TLS_FALLBACK_SCSV if the service is providing TLSv1.0+
TCP Timestamps Information Disclosure	2.6 (Low)	The remote host implements TCP timestamps and therefore allows to compute the uptime. A side effect of this feature is that the uptime of the remote host can sometimes be computed.	To disable TCP timestamps on linux add the line 'net.ipv4.tcp_timestamps = 0' to /etc/sysctl.conf. Execute 'sysctl -p' to apply the settings at runtime. To disable TCP timestamps on Windows execute 'netsh int tcp set global timestamps=disabled'. Starting with Windows Server 2008 and Vista, the timestamp can not be completely disabled. The default behavior of the TCP/IP stack on this Systems is to not use the Timestamp options when initiating TCP connections, but use them if the TCP peer that is initiating communication includes them in their synchronize (SYN) segment.
Weak MAC Algorithm(s) Supported (SSH)	2.6 (Low)	The remote SSH server supports the following weak client-to-server MAC algorithm(s): hmac-md5, hmac-md5-96, hmac-sha1-96, umac-64@openssh.com	Disable the reported weak MAC algorithm(s).
ICMP Timestamp Reply Information Disclosure	2.1 (Low)	The following response / ICMP packet has been received: ICMP Type: 14 and ICMP Code: 0. The Timestamp Reply is an ICMP message which replies to a Timestamp message. It consists of the originating timestamp sent by the sender of the Timestamp as well as a receive timestamp and a transmit timestamp. This information could theoretically be used to exploit weak time-based random number generators in other services.	Disable the support for ICMP timestamp on the remote host completely. Protect the remote host by a firewall, and block ICMP packets passing through the firewall in either direction (either completely or only for untrusted networks)