Description
In the Linux kernel, the following vulnerability has been resolved: sctp: auth: verify auth requirement when auth_chunk is NULL sctp_auth_chunk_verify() returns true unconditionally when chunk->auth_chunk is NULL, silently skipping authentication. This is incorrect when: 1. skb_clone() failed in the BH receive path, leaving auth_chunk NULL. In sctp_endpoint_bh_rcv() asoc is NULL for new connections, so the early sctp_auth_recv_cid() check cannot catch this. 2. No AUTH chunk precedes COOKIE-ECHO, so skb_clone() is never called and auth_chunk remains NULL. Fix by checking sctp_auth_recv_cid() when auth_chunk is NULL: if authentication is required, return false to drop the chunk; otherwise continue normally.
References8
- git.kernel.org/stable/c/18957373920caf5cdaf5cf32e5d1d7a99ca7700a
- git.kernel.org/stable/c/28c5fdce9dd955d2baf5e28987819b6d7cfaf646
- git.kernel.org/stable/c/5a022ac51ad83b4ce6c898f4b9eefc65bd26b247
- git.kernel.org/stable/c/6caf0e8590c0bf05a76b0d387726adf3a6f3725c
- git.kernel.org/stable/c/83f5031f2a6a49d696eb4cc0898345d12f9c6451
- git.kernel.org/stable/c/8e04823c120b376ef7dab14b60ebf6823aa16c14
- git.kernel.org/stable/c/a129792b3aef15002746c13522781d92ed3522c3
- git.kernel.org/stable/c/ec2e157fc9678a9bc411305a25aec3fd337d7efb
Metrics
- CVSS 3.1
-
9.8
CRITICAL
Score source: CNA
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - EPSS — exploit probability
- 1% percentile: 48 · as of 12 November 2026
- CWE
- CWE-287
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