In the Linux kernel, the following vulnerability has been resolved:
nfc: llcp: bound SNL TLV parsing to the skb and add length checks
nfc_llcp_recv_snl() walked the SNL TLV list using a u16 offset/length
pair derived from skb->len, without bounding reads to the actual skb
data. Three problems followed:
- For a short frame (skb->len < LLCP_HEADER_SIZE), tlv_len underflowed.
- The per-TLV header (type, length) was read without checking that two
bytes remained.
- A declared TLV length could run past the end of the buffer, and an
SDREQ with length == 0 made "service_name_len = length - 1" underflow
(size_t), driving an out-of-bounds read in the following strncmp() /
nfc_llcp_sock_from_sn(). The SDRES case likewise read tlv[2]/tlv[3]
without a length check.
A nearby NFC device can reach this without authentication; LLCP link
activation happens automatically after NFC-DEP.
Walk the TLV list by pointer, bounded by skb_tail_pointer() over the
linear skb data, and validate each TLV declared length before use. Add
explicit length checks for SDREQ (>= 1) and SDRES (exactly 2).
Found by 0sec automated security-research tooling (https://0sec.ai).
CISA SSVCTrack at low or medium mission impact; Track or Attend at high (mission-essential systems).
No fix is confirmed yet. Restrict network exposure of the affected system or apply the vendor's mitigation within your standard update timelines at low or medium mission impact and sooner than that at high, and watch the vendor's advisory for the fix.
Exploitation none (no KEV listing, exploit record or EPSS ≥ 50%) · Automatable unknown (not published for this CVE) · Technical impact partial (CVSS below 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