CVE-2010-0731 in gnutls
Summary
by MITRE
The gnutls_x509_crt_get_serial function in the GnuTLS library before 1.2.1, when running on big-endian, 64-bit platforms, calls the asn1_read_value with a pointer to the wrong data type and the wrong length value, which allows remote attackers to bypass the certificate revocation list (CRL) check and cause a stack-based buffer overflow via a crafted X.509 certificate, related to extraction of a serial number.
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Analysis
by VulDB Data Team • 05/03/2026
The vulnerability described in CVE-2010-0731 represents a critical flaw in the GnuTLS cryptographic library that affects systems running big-endian, 64-bit architectures. This issue stems from improper handling of X.509 certificate serial numbers during the certificate validation process, specifically within the gnutls_x509_crt_get_serial function. The flaw occurs when the library attempts to extract serial number information from X.509 certificates, creating a scenario where remote attackers can manipulate certificate validation mechanisms and potentially execute arbitrary code. The vulnerability is particularly concerning because it undermines the fundamental security assurances provided by certificate-based authentication systems, allowing attackers to bypass crucial certificate revocation list checks that are essential for maintaining trust in digital certificates.
The technical root cause of this vulnerability lies in the improper parameter handling within the asn1_read_value function call, where the GnuTLS library passes incorrect pointer types and length values when processing certificate serial numbers. This misconfiguration results in a stack-based buffer overflow condition that can be exploited through carefully crafted X.509 certificates. The flaw specifically manifests on big-endian 64-bit platforms due to differences in memory layout and data type handling between architectures, making systems with these configurations particularly susceptible. The buffer overflow occurs because the library attempts to read data into a buffer that is insufficiently sized for the actual data being processed, creating opportunities for attackers to overwrite adjacent memory locations and potentially execute malicious code. This type of vulnerability falls under CWE-121, stack-based buffer overflow, and represents a classic example of improper input validation in cryptographic libraries.
The operational impact of this vulnerability extends beyond simple certificate validation failures, as it enables attackers to bypass critical certificate revocation mechanisms that are fundamental to secure communications. When exploited, the vulnerability allows for the execution of arbitrary code on affected systems, potentially leading to complete system compromise. The ability to bypass CRL checks means that attackers can present revoked certificates as valid, undermining the entire certificate trust model that secure communication protocols depend upon. This vulnerability affects any system using GnuTLS versions prior to 1.2.1 on big-endian 64-bit platforms, including web servers, email servers, and other network services that rely on SSL/TLS certificate validation. The remote nature of the exploit means that attackers do not require local access to the system, making this vulnerability particularly dangerous in networked environments where certificate validation is critical for securing communications.
Mitigation strategies for this vulnerability require immediate patching of affected GnuTLS installations to version 1.2.1 or later, which contains the necessary fixes for the buffer overflow and incorrect parameter handling. System administrators should also implement network monitoring to detect potential exploitation attempts and consider temporary disabling of vulnerable services until patches are applied. The vulnerability demonstrates the importance of proper input validation and memory management in cryptographic libraries, as highlighted by ATT&CK technique T1059 for command and script injection through buffer overflow exploitation. Organizations should also review their certificate management practices and ensure that systems are configured to validate certificates against current CRLs and OCSP responses. Additionally, implementing proper network segmentation and access controls can help limit the potential impact of successful exploitation attempts, while regular security audits should verify that all cryptographic libraries are updated to their latest secure versions to prevent similar vulnerabilities from being introduced in the future.