Implement fragment size validation#39
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A heap-based buffer overflow vulnerability exists here due to insufficient validation of fragment size values. A specially crafted packet with malformed fragment headers can cause negative or oversized fragment_bytes values to be passed to memcpy(), resulting in out-of-bounds memory writes. This vulnerability may allow remote attackers to cause a denial of service or potentially achieve arbitrary code execution. Signed-off-by: Jorn Segers <131166816+SegersJorn@users.noreply.github.com>
gafferongames
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Feb 26, 2026
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Thanks for the fix!
Please adjust to match coding standard in the file surrounding it. Also, it shouldn't be an error (according to log policies in reliable) because it's not something the user controls. It should be a debug log (off by default), because it is a handled attack that is out of control of the user writing the software. -- thanks!
Signed-off-by: Jorn Segers <131166816+SegersJorn@users.noreply.github.com>
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Thank you! |
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I'm glad to help! For context, I came across this bug by fuzzing with AFL++ for my ongoing masters thesis on fuzzing multiplayer video games. |
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A heap-based buffer overflow vulnerability exists here due to insufficient validation of fragment size values. A specially crafted packet with malformed fragment headers can cause negative or oversized fragment_bytes values to be passed to memcpy(), resulting in out-of-bounds memory writes. This vulnerability may allow remote attackers to cause a denial of service or potentially achieve arbitrary code execution.