CVE-2014-8564 in GnuTLS
Summary
by MITRE
The _gnutls_ecc_ansi_x963_export function in gnutls_ecc.c in GnuTLS 3.x before 3.1.28, 3.2.x before 3.2.20, and 3.3.x before 3.3.10 allows remote attackers to cause a denial of service (out-of-bounds write) via a crafted (1) Elliptic Curve Cryptography (ECC) certificate or (2) certificate signing requests (CSR), related to generating key IDs.
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Analysis
by VulDB Data Team • 12/09/2024
The vulnerability identified as CVE-2014-8564 represents a critical out-of-bounds write flaw in the GnuTLS cryptographic library that affects multiple versions including 3.x before 3.1.28, 3.2.x before 3.2.20, and 3.3.x before 3.3.10. This issue stems from the _gnutls_ecc_ansi_x963_export function within the gnutls_ecc.c file, which handles elliptic curve cryptography operations. The flaw manifests when processing crafted ECC certificates or certificate signing requests, creating a scenario where malicious inputs can trigger memory corruption. The vulnerability specifically targets the key ID generation process, which is fundamental to cryptographic certificate handling and identity verification within TLS/SSL implementations.
The technical nature of this vulnerability places it squarely within CWE-121, which describes heap-based buffer overflow conditions, and more specifically aligns with CWE-787, representing out-of-bounds write vulnerabilities. The flaw operates through a classic buffer management error where the function fails to properly validate input data lengths when exporting ECC key information, leading to memory corruption that can be exploited remotely. Attackers can craft malicious certificates or CSRs with malformed ECC parameters that cause the function to write data beyond allocated memory boundaries, potentially resulting in application crashes or more severe system compromise. This vulnerability demonstrates the dangerous intersection of cryptographic library implementation flaws and denial of service attacks.
The operational impact of CVE-2014-8564 extends beyond simple service disruption to encompass potential system stability and security compromise across environments relying on GnuTLS for secure communications. Systems utilizing affected GnuTLS versions in web servers, mail servers, VPN services, or any application handling SSL/TLS connections become vulnerable to remote exploitation. The out-of-bounds write condition can cause applications to crash unpredictably, potentially leading to extended service downtime and denial of service for legitimate users. From an attacker perspective, this vulnerability maps to ATT&CK technique T1499.004, specifically focusing on network denial of service, and represents a critical weakness in cryptographic infrastructure that could undermine trust in secure communications. The vulnerability's remote exploitability means that attackers need only send specially crafted certificates or CSRs to trigger the memory corruption, making it particularly dangerous in production environments.
Mitigation strategies for CVE-2014-8564 primarily focus on immediate version upgrades to patched releases of GnuTLS, specifically versions 3.1.28, 3.2.20, or 3.3.10 and later. System administrators should prioritize patching all affected systems, including web servers, mail servers, and any applications using the vulnerable library. Additionally, implementing certificate validation controls and monitoring for suspicious certificate requests can help detect potential exploitation attempts. Network-level defenses such as intrusion detection systems can be configured to monitor for patterns consistent with this vulnerability, though the most effective mitigation remains timely software updates. Organizations should also consider implementing certificate pinning mechanisms and robust certificate validation policies to reduce the impact of potential exploitation attempts. The vulnerability highlights the importance of maintaining up-to-date cryptographic libraries and demonstrates how seemingly minor implementation flaws in security-critical components can create significant operational risks across enterprise networks.