CVE-2012-1663 in gnutls
Summary
by MITRE
Double free vulnerability in libgnutls in GnuTLS before 3.0.14 allows remote attackers to cause a denial of service (application crash) or possibly have unspecified other impact via a crafted certificate list.
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Analysis
by VulDB Data Team • 01/02/2025
The CVE-2012-1663 vulnerability represents a critical double free error in the GnuTLS library version 3.0.13 and earlier, which exposes systems to potential remote exploitation. This flaw exists within the certificate processing functionality of the cryptographic library that is widely used for implementing secure communications in various applications and operating systems. The vulnerability stems from improper memory management during the handling of certificate lists, where the same memory block gets freed twice under specific conditions, leading to unpredictable behavior in the application.
The technical implementation of this vulnerability involves a flaw in how GnuTLS processes certificate chains, particularly when encountering malformed or crafted certificate lists. When a maliciously constructed certificate list is presented to a vulnerable GnuTLS implementation, the library's memory management routines fail to properly track memory allocations and deallocations. This results in a double free condition where the same memory address is passed to the free() function twice, causing heap corruption that can lead to application crashes or potentially more severe consequences depending on the execution context and memory layout.
From an operational perspective, this vulnerability presents significant risks to systems relying on GnuTLS for secure communications, including web servers, email servers, and any application that uses the library for SSL/TLS implementations. The remote nature of the attack means that adversaries can exploit this vulnerability without requiring local access or authentication, making it particularly dangerous in networked environments. The potential impacts extend beyond simple denial of service to include possible code execution or information disclosure, depending on how the heap corruption manifests in different system configurations and memory layouts.
The vulnerability aligns with CWE-415, which describes improper double free conditions in memory management, and can be mapped to ATT&CK technique T1190 for exploitation of remote services through memory corruption vulnerabilities. Organizations using affected versions of GnuTLS should prioritize immediate patching to version 3.0.14 or later, as the fix addresses the core memory management issues in the certificate processing code. Additional mitigations include implementing network segmentation to limit exposure, monitoring for unusual certificate processing patterns, and ensuring that all systems using GnuTLS are regularly updated with security patches. The vulnerability underscores the critical importance of proper memory management in cryptographic libraries and highlights the need for thorough testing of edge cases in security-sensitive code components.