CVE-2018-5122 in Firefox
Summary
by MITRE
A potential integer overflow in the "DoCrypt" function of WebCrypto was identified. If a means was found of exploiting it, it could result in an out-of-bounds write. This vulnerability affects Firefox < 58.
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Analysis
by VulDB Data Team • 07/21/2024
The vulnerability identified as CVE-2018-5122 represents a critical integer overflow condition within the WebCrypto implementation of Mozilla Firefox browsers. This flaw exists specifically within the "DoCrypt" function which handles cryptographic operations, making it a significant concern for web security implementations. The vulnerability affects Firefox versions prior to 58, indicating that it was present in a substantial portion of the browser user base during the affected period. Integer overflows in cryptographic functions are particularly dangerous because they can lead to memory corruption issues that may be exploited for arbitrary code execution or other malicious activities.
The technical nature of this vulnerability stems from improper input validation within the cryptographic processing pipeline. When the DoCrypt function processes certain cryptographic parameters, it fails to properly check for integer overflow conditions that could occur during arithmetic operations involving large numbers or buffer sizes. This oversight creates a scenario where an attacker could manipulate input data to cause the function to calculate an incorrect buffer size or memory offset. The resulting integer overflow can then translate into an out-of-bounds write condition, where the application attempts to write data beyond the allocated memory boundaries. Such memory corruption vulnerabilities are classified under CWE-190 as "Integer Overflow or Wraparound" and can be leveraged for privilege escalation or system compromise.
The operational impact of this vulnerability extends beyond simple browser security concerns as it affects the core cryptographic capabilities that secure web communications. WebCrypto API implementations are fundamental to modern web security protocols including HTTPS, digital signatures, and secure authentication mechanisms. When an attacker successfully exploits this integer overflow, they could potentially execute arbitrary code within the browser context, leading to complete system compromise. The vulnerability's exploitation requires careful crafting of input parameters to trigger the overflow condition, but once achieved, it could enable attackers to bypass security controls and access sensitive information. This aligns with ATT&CK technique T1059.007 for Command and Scripting Interpreter and T1068 for Exploitation for Privilege Escalation, making it particularly dangerous in targeted attack scenarios.
Mitigation strategies for CVE-2018-5122 primarily focus on immediate browser updates to version 58 or later, which contain the necessary patches to address the integer overflow condition. Organizations should implement comprehensive patch management procedures to ensure all affected systems are updated promptly. Additional defensive measures include network monitoring for suspicious cryptographic operations and implementing web application firewalls that can detect anomalous input patterns. The vulnerability highlights the importance of rigorous input validation in cryptographic implementations and demonstrates the need for thorough security testing of security-critical functions. Security teams should also consider implementing runtime protections such as address space layout randomization and stack canaries to mitigate potential exploitation attempts. Regular security assessments of web browser configurations and cryptographic implementations remain essential practices to prevent similar vulnerabilities from being exploited in the future.