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:
- 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.
- 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.
CISA SSVCTrack at low or medium mission impact; Track* or Attend at high (mission-essential systems).
A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.
Exploitation none (no KEV listing, exploit record or EPSS ≥ 50%) · Automatable unknown (not published for this CVE) · Technical impact total (CVSS ≥ 9.0). Mission impact is CISA's Mission & Well-being decision point, and only you can judge it: high means the affected system is essential to your organisation's mission, or its compromise could cause irreversible harm to people. CISA's decision table