High-Severity Remote Code Execution Vulnerability Patched in OpenSSL

"When parsing CMS AuthEnvelopedData structures that use AEAD ciphers such as AES-GCM, the IV (Initialization Vector) encoded in the ASN.1 parameters is copied into a fixed-size stack buffer without verifying that its length fits the destination. An attacker can supply a crafted CMS message with an oversized IV, causing a stack-based out-of-bounds write before any authentication or tag verification occurs. Applications and services that parse untrusted CMS or PKCS#7 content using AEAD ciphers (e.g., S/MIME AuthEnvelopedData with AES-GCM) are vulnerable."

"OpenSSL updates released on Tuesday patch a dozen vulnerabilities, including a high-severity remote code execution flaw. All 12 vulnerabilities patched in the open source SSL/TLS toolkit were discovered by cybersecurity firm Aisle, which used an autonomous analyzer to identify the security holes. The high-severity issue is tracked as CVE-2025-15467 and it has been described as a stack buffer overflow that could lead to a crash (DoS condition) or remote code execution in certain conditions."

OpenSSL released updates that patch twelve vulnerabilities identified by cybersecurity firm Aisle using an autonomous analyzer. The most severe issue, CVE-2025-15467, is a stack buffer overflow in CMS AuthEnvelopedData parsing when AEAD ciphers like AES-GCM are used; an oversized IV in ASN.1 parameters is copied into a fixed-size stack buffer, enabling a stack-based out-of-bounds write before authentication. Attackers can trigger the overflow without valid key material, and remote code execution depends on platform and toolchain mitigations. The releases also fix CVE-2025-11187 (moderate), several low-severity DoS and information-exposure flaws, and six issues addressed prior to release.

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