CVE-2017-7792 in Firefox
Summary
by MITRE
A buffer overflow will occur when viewing a certificate in the certificate manager if the certificate has an extremely long object identifier (OID). This results in a potentially exploitable crash. This vulnerability affects Thunderbird < 52.3, Firefox ESR < 52.3, and Firefox < 55.
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Analysis
by VulDB Data Team • 11/26/2025
The vulnerability identified as CVE-2017-7792 represents a critical buffer overflow condition that manifests within the certificate management functionality of Mozilla Firefox and Thunderbird applications. This flaw specifically occurs when the software attempts to process certificates containing exceptionally long object identifiers that exceed the allocated buffer space. The issue stems from inadequate input validation mechanisms within the certificate parsing routines, where the application fails to properly sanitize or limit the length of object identifiers before attempting to store or display them in memory buffers. The vulnerability affects multiple versions of the Firefox browser and its extended support release line, with the affected versions being Firefox < 55 and Firefox ESR < 52.3, as well as Thunderbird < 52.3. The buffer overflow condition creates a potential crash scenario that could be exploited by malicious actors to execute arbitrary code within the context of the affected application. This type of vulnerability falls under the common weakness enumeration CWE-121, which classifies buffer overflow conditions as a fundamental security flaw. The attack surface is particularly concerning as it involves the certificate management system, which is frequently accessed during secure communications and authentication processes. The operational impact extends beyond simple application instability, as the vulnerability could be leveraged in targeted attacks against users who encounter specially crafted malicious certificates. The certificate manager functionality is commonly used during secure web browsing, email encryption, and various authentication scenarios, making this vulnerability particularly dangerous when exploited in the context of man-in-the-middle attacks or certificate spoofing attempts. The flaw demonstrates a classic stack-based buffer overflow pattern where insufficient bounds checking allows an attacker to overwrite adjacent memory locations, potentially leading to privilege escalation or code execution. From an adversarial perspective, this vulnerability aligns with ATT&CK technique T1552.001, which involves the exploitation of credential access mechanisms through software vulnerabilities. The affected software components represent critical infrastructure elements for secure communications, making this vulnerability particularly attractive to threat actors targeting enterprise environments or users who rely heavily on secure browser functionality. Security researchers have noted that the exploitation of this vulnerability requires specific conditions, including the presence of a malicious certificate with an overly long OID, but the potential for remote code execution makes it a significant concern for users of the affected versions.
The technical implementation of this vulnerability involves the certificate parsing subsystem within the Mozilla application framework, where object identifiers are processed without adequate length validation. When the certificate manager attempts to display a certificate containing an extremely long OID, the application's internal buffer allocation mechanism fails to accommodate the excessive data size, resulting in memory corruption. This condition typically manifests as a segmentation fault or access violation when the program attempts to write beyond the allocated memory boundaries. The specific memory layout and buffer sizes involved in this vulnerability are particularly problematic because they occur in the application's user interface rendering components, which are frequently accessed during normal browsing operations. The vulnerability's exploitability is enhanced by the fact that certificate management is a routine function that users perform regularly, increasing the attack surface for potential exploitation. The buffer overflow occurs in the context of certificate display operations, which means that simply viewing a maliciously crafted certificate could trigger the vulnerability. This makes the attack vector particularly stealthy and difficult to detect, as users may not realize they have encountered a malicious certificate until after the system has crashed or been compromised. The flaw's presence in both Firefox and Thunderbird applications indicates a systemic issue within the certificate handling codebase, suggesting that similar vulnerabilities may exist in related components. The memory corruption pattern associated with this vulnerability is consistent with classic buffer overflow exploitation techniques that have been documented in various security research publications. The vulnerability's classification as a remote code execution risk stems from the fact that the malicious certificate could be delivered through various attack vectors including compromised websites, email attachments, or man-in-the-middle scenarios.
Mitigation strategies for CVE-2017-7792 should prioritize immediate software updates to versions that contain the necessary patches for the buffer overflow condition. Users of affected software versions must upgrade to Firefox 55 or later, Firefox ESR 52.3 or later, and Thunderbird 52.3 or later to eliminate the risk of exploitation. The patch implementations typically involve adding proper input validation for object identifier lengths, implementing bounds checking mechanisms, and ensuring that buffer allocations accommodate the maximum possible OID length. Organizations should implement comprehensive patch management policies that include regular security updates for all browser and email client software components. Network administrators should consider implementing additional security controls such as certificate pinning, web application firewalls, and certificate monitoring systems to detect and prevent exploitation attempts. The vulnerability's remediation also involves updating certificate validation procedures to include more rigorous checks for malformed certificates that could trigger buffer overflow conditions. Security teams should monitor for indicators of compromise related to this vulnerability, including unusual certificate processing patterns or system crashes occurring during certificate display operations. The implementation of automated vulnerability scanning tools can help identify systems running vulnerable versions of the affected software. Organizations should also consider implementing user education programs to raise awareness about the risks of encountering untrusted certificates and the importance of keeping software up to date. The vulnerability's impact on enterprise security environments necessitates coordinated patch deployment across all affected systems, with particular attention to systems that handle sensitive data or serve as gateways for secure communications. Regular security assessments should include verification that the patched versions have been properly deployed and are functioning correctly. The mitigation approach should also incorporate monitoring for any attempts to exploit this vulnerability through certificate-based attacks, as the threat landscape continues to evolve with new exploitation techniques targeting similar buffer overflow conditions.