Skip to content

Fix out-of-bounds read in GtpV2Layer with truncated TEID-present header #2181

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
vsaraikin wants to merge 2 commits into
base: dev
Choose a base branch
from
+20 −0
Open

Fix out-of-bounds read in GtpV2Layer with truncated TEID-present header #2181

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
07d7edd
Fix out-of-bounds read in GtpV2Layer with truncated TEID-present header
vsaraikin Jul 10, 2026
346fb54
Merge branch 'dev' into fix/gtpv2-teid-present-oob-read
Dimi1010 Jul 18, 2026
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
8 changes: 8 additions & 0 deletions Packet++/src/GtpLayer.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -1027,6 +1027,14 @@ namespace pcpp
return false;
}

// When the TEID-present flag is set, the fixed header carries the 4-byte TEID before
// the sequence-number word, so the minimum length grows accordingly. Without this
// check accessors such as getSequenceNumber() would read past the buffer (GH #2171).
if (header->teidPresent && dataSize < sizeof(gtpv2_basic_header) + 2 * sizeof(uint32_t))
{
return false;
}

return true;
}

Expand Down
12 changes: 12 additions & 0 deletions Tests/Packet++Test/Tests/GtpTests.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -421,6 +421,18 @@ PTF_TEST_CASE(GtpV2LayerParsingTest)
PTF_ASSERT_EQUAL(infoElement.getCRFlag(), 7);
PTF_ASSERT_EQUAL(infoElement.getInstance(), 12);
}

// GH #2171: a TEID-present header that is long enough for the basic header + TEID but not
// for the sequence-number word must be rejected, otherwise getSequenceNumber() reads OOB.
{
// version 2, TEID-present flag set, only 8 bytes (basic header + TEID, missing seq word)
const uint8_t truncatedTeidPresent[] = { 0x48, 0x20, 0x00, 0x08, 0xde, 0xad, 0xbe, 0xef };
PTF_ASSERT_FALSE(pcpp::GtpV2Layer::isDataValid(truncatedTeidPresent, sizeof(truncatedTeidPresent)));

// the same header with the 4-byte sequence word present (12 bytes) is accepted
const uint8_t fullTeidPresent[] = { 0x48, 0x20, 0x00, 0x0c, 0xde, 0xad, 0xbe, 0xef, 0x00, 0x00, 0x00, 0x00 };
PTF_ASSERT_TRUE(pcpp::GtpV2Layer::isDataValid(fullTeidPresent, sizeof(fullTeidPresent)));
}
} // GtpV2LayerParsingTest

PTF_TEST_CASE(GtpV2LayerCreationTest)
Expand Down
Loading