Out-of-bounds Write Affecting kernel-tools-debuginfo package, versions <1:6.1.155-176.282.amzn2023


Severity

Recommended
high

Based on Amazon Linux security rating.

Threat Intelligence

Exploit Maturity
Proof of Concept
EPSS
0.03% (7th percentile)

Do your applications use this vulnerable package?

In a few clicks we can analyze your entire application and see what components are vulnerable in your application, and suggest you quick fixes.

Test your applications
  • Snyk IDSNYK-AMZN2023-KERNELTOOLSDEBUGINFO-13731196
  • published29 Oct 2025
  • disclosed4 Oct 2025

Introduced: 4 Oct 2025

NewCVE-2025-39946  (opens in a new tab)
CWE-787  (opens in a new tab)

How to fix?

Upgrade Amazon-Linux:2023 kernel-tools-debuginfo to version 1:6.1.155-176.282.amzn2023 or higher.
This issue was patched in ALAS2023-2025-1223.

NVD Description

Note: Versions mentioned in the description apply only to the upstream kernel-tools-debuginfo package and not the kernel-tools-debuginfo package as distributed by Amazon-Linux. See How to fix? for Amazon-Linux:2023 relevant fixed versions and status.

In the Linux kernel, the following vulnerability has been resolved:

tls: make sure to abort the stream if headers are bogus

Normally we wait for the socket to buffer up the whole record before we service it. If the socket has a tiny buffer, however, we read out the data sooner, to prevent connection stalls. Make sure that we abort the connection when we find out late that the record is actually invalid. Retrying the parsing is fine in itself but since we copy some more data each time before we parse we can overflow the allocated skb space.

Constructing a scenario in which we're under pressure without enough data in the socket to parse the length upfront is quite hard. syzbot figured out a way to do this by serving us the header in small OOB sends, and then filling in the recvbuf with a large normal send.

Make sure that tls_rx_msg_size() aborts strp, if we reach an invalid record there's really no way to recover.

CVSS Base Scores

version 3.1