CVE-2006-2778 in Firefox
Summary
by MITRE
The crypto.signText function in Mozilla Firefox and Thunderbird before 1.5.0.4 allows remote attackers to execute arbitrary code via certain optional Certificate Authority name arguments, which causes an invalid array index and triggers a buffer overflow.
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Analysis
by VulDB Data Team • 01/20/2025
The vulnerability identified as CVE-2006-2778 represents a critical buffer overflow flaw within the cryptographic signing functionality of Mozilla Firefox and Thunderbird applications. This issue affects versions prior to 1.5.0.4 and specifically targets the crypto.signText function that handles digital signature operations. The vulnerability arises from improper input validation when processing Certificate Authority name arguments, creating a scenario where maliciously crafted inputs can lead to arbitrary code execution on affected systems. The flaw manifests when the application processes optional CA name parameters, causing an invalid array index that ultimately triggers a buffer overflow condition.
The technical implementation of this vulnerability stems from inadequate bounds checking within the crypto.signText function's handling of Certificate Authority arguments. When an attacker supplies malformed or specially crafted CA name parameters, the application fails to properly validate the input length and structure before using these values in array indexing operations. This validation failure results in an invalid array index being calculated, which subsequently leads to memory corruption through a buffer overflow. The overflow occurs in the application's memory management system where the improperly validated input causes data to be written beyond the allocated buffer boundaries, potentially allowing attackers to overwrite critical memory locations including return addresses and function pointers.
From an operational perspective, this vulnerability presents a severe threat to users of affected Mozilla applications since it enables remote code execution without requiring any user interaction beyond visiting a malicious website or opening a specially crafted email message. The attack vector is particularly dangerous because it leverages the legitimate cryptographic functionality of the applications, making it more difficult to detect through standard security monitoring. The vulnerability is classified under CWE-121 as a stack-based buffer overflow, and aligns with ATT&CK technique T1059.007 for execution through command and scripting interpreter, as successful exploitation could allow attackers to execute arbitrary commands on the compromised system. The impact extends beyond individual user compromise to potentially enable broader network infiltration and data exfiltration activities.
Mitigation strategies for CVE-2006-2778 primarily focus on immediate version updates to Mozilla Firefox and Thunderbird 1.5.0.4 or later, which contain the necessary patches to address the input validation flaws. Organizations should implement comprehensive patch management procedures to ensure all affected systems receive updates promptly. Additional protective measures include network-level filtering to block access to known malicious domains, implementation of application whitelisting policies that restrict execution of unsigned code, and enhanced email security filtering to prevent delivery of malicious content that could trigger the vulnerability. Security monitoring should be enhanced to detect unusual patterns in cryptographic operations or memory allocation behaviors that might indicate exploitation attempts. The vulnerability also underscores the importance of input validation practices and proper memory management in cryptographic libraries, emphasizing that even legitimate security features can become attack vectors when proper bounds checking is not implemented.