CVE-2013-0791 in Firefox
Summary
by MITRE
The CERT_DecodeCertPackage function in Mozilla Network Security Services (NSS), as used in Mozilla Firefox before 20.0, Firefox ESR 17.x before 17.0.5, Thunderbird before 17.0.5, Thunderbird ESR 17.x before 17.0.5, SeaMonkey before 2.17, and other products, allows remote attackers to cause a denial of service (out-of-bounds read and memory corruption) via a crafted certificate.
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Analysis
by VulDB Data Team • 05/06/2021
The vulnerability identified as CVE-2013-0791 represents a critical memory corruption flaw within Mozilla Network Security Services NSS library that affected multiple Mozilla products including Firefox, Thunderbird, and SeaMonkey. This issue stems from improper handling of certificate data during the decoding process, specifically within the CERT_DecodeCertPackage function. The flaw enables remote attackers to manipulate certificate packages in ways that trigger out-of-bounds memory reads and subsequent memory corruption, potentially leading to system instability and denial of service conditions. The vulnerability exists in versions of NSS prior to 3.15 and affects all major Mozilla browser and email client products that rely on this cryptographic library for secure communications.
The technical implementation of this vulnerability involves a classic buffer over-read condition where the CERT_DecodeCertPackage function fails to properly validate certificate package boundaries before processing certificate data. When processing a maliciously crafted certificate, the function attempts to read memory locations beyond the allocated buffer boundaries, causing unpredictable behavior and potential memory corruption. This type of flaw falls under CWE-125, which specifically addresses out-of-bounds read conditions, and can be classified as a memory safety vulnerability within the broader category of software faults that compromise system integrity. The function's inadequate input validation allows attackers to construct certificate packages with malformed data structures that exceed expected boundaries, leading to the exploitation of memory access violations.
From an operational perspective, this vulnerability presents significant risk to organizations relying on affected Mozilla products for secure communications. The remote exploitation capability means that attackers can trigger denial of service conditions without requiring local system access or user interaction, making it particularly dangerous in enterprise environments where these applications are widely deployed. The memory corruption aspect introduces potential for more severe consequences including application crashes, system instability, and in some cases, potential privilege escalation or code execution. The vulnerability affects not just individual user systems but also enterprise infrastructure where certificate validation is critical for secure network communications, potentially disrupting services and compromising the availability of secure communication channels.
Mitigation strategies for CVE-2013-0791 primarily focus on immediate software updates and patches provided by Mozilla. Organizations should prioritize updating all affected Mozilla products to versions that include the patched NSS library, specifically ensuring Firefox 20.0+, Thunderbird 17.0.5+, and SeaMonkey 2.17+. System administrators should also implement network monitoring to detect potential exploitation attempts through malformed certificate traffic patterns. Additional protective measures include configuring certificate validation policies that limit trust to known good certificate authorities and implementing network segmentation to reduce the attack surface. The vulnerability demonstrates the importance of robust input validation in cryptographic libraries and highlights the need for continuous security auditing of security-critical components. Organizations should also consider implementing intrusion detection systems that can identify unusual certificate processing patterns that may indicate exploitation attempts, aligning with ATT&CK technique T1059.007 for command and scripting interpreter execution that may occur during exploitation activities.