CVE-2022-49094

A flaw was discovered in the Linux kernel’s TLS subsystem (net/tls) related to AES128‑CCM decryption in the decrypt_internal() function. The issue stems from a mismatch between the initialization vector (IV) buffer size (tls_ctx->rx.iv) set to 12 bytes in tls_set_sw_offload() and the 16-byte IV size returned by crypto_aead_ivsize("ccm(aes)"). As a result, a memcpy() operation copies 16 bytes into a 12-byte buffer, causing a slab out-of-bounds access. A local attacker with low privileges could exploit this flaw to trigger memory corruption, leading to system instability or denial of service.

This vulnerability is rated as having Moderate impact because it requires local access with specific socket configuration to trigger a denial of service, preventing direct remote exploitation or privilege escalation. On Red Hat Enterprise Linux, the flaw is present in the kernel TLS implementation and is reachable only when an application or unprivileged user establishes a session explicitly configured for AES-128-CCM under TLS 1.3. As a result, typical server workloads that do not use in-kernel cryptographic offload with this specific cipher suite remain unaffected during normal operation.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.