CVE-2009-3075 in Firefox
Summary
by MITRE
Multiple unspecified vulnerabilities in the JavaScript engine in Mozilla Firefox before 3.0.14 and 3.5.x before 3.5.2, Thunderbird before 2.0.0.24, and SeaMonkey before 1.1.19 allow remote attackers to cause a denial of service (memory corruption and application crash) or possibly execute arbitrary code via vectors related to use of mutable strings in the js_StringReplaceHelper function in js/src/jsstr.cpp, and unknown vectors.
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Analysis
by VulDB Data Team • 08/22/2021
The vulnerability identified as CVE-2009-3075 represents a critical security flaw within the JavaScript engine of several Mozilla applications including Firefox, Thunderbird, and SeaMonkey. This issue stems from improper handling of mutable strings within the js_StringReplaceHelper function located in js/src/jsstr.cpp, affecting versions prior to Firefox 3.0.14 and 3.5.x before 3.5.2, Thunderbird 2.0.0.24, and SeaMonkey 1.1.19. The flaw manifests as unspecified vulnerabilities that can be exploited by remote attackers to trigger either denial of service conditions through memory corruption and application crashes, or potentially more severe arbitrary code execution. The vulnerability is categorized under CWE-125 as an out-of-bounds read condition, which falls within the broader category of memory safety issues that have historically been exploited for privilege escalation and remote code execution attacks. The JavaScript engine's string handling mechanisms are particularly susceptible to manipulation due to the complex nature of mutable string operations in dynamic scripting environments.
The technical exploitation of this vulnerability occurs through the manipulation of string replacement operations within the JavaScript engine's internal code structure. When the js_StringReplaceHelper function processes mutable strings, it fails to properly validate or sanitize input parameters, creating opportunities for attackers to craft malicious JavaScript code that can corrupt memory structures and cause unpredictable behavior. This type of vulnerability is particularly dangerous because it operates within the core execution environment of web browsers, where JavaScript code is interpreted and executed. The memory corruption issues can lead to heap corruption, stack smashing, or other memory management failures that may result in application crashes or, in more sophisticated attacks, provide attackers with opportunities to inject and execute arbitrary code. The attack vectors related to mutable string usage suggest that the vulnerability can be triggered through various JavaScript string manipulation methods, making it difficult to fully mitigate without addressing the underlying engine flaw.
The operational impact of CVE-2009-3075 extends beyond simple denial of service conditions to potentially enable complete system compromise. When exploited successfully, this vulnerability can allow remote attackers to execute arbitrary code on affected systems with the privileges of the user running the vulnerable browser application. This capability directly maps to ATT&CK technique T1059.007 for JavaScript and T1203 for Exploitation for Client Execution, as attackers can leverage the browser's JavaScript engine to deliver malicious payloads. The vulnerability affects a wide range of Mozilla-based applications, making it particularly dangerous in enterprise environments where multiple applications may be running with varying degrees of security hardening. Organizations using these affected versions face significant risk of data breaches, system compromise, and potential lateral movement within their networks, especially when users visit malicious websites or open compromised email attachments containing malicious JavaScript code.
Mitigation strategies for CVE-2009-3075 primarily focus on immediate patch deployment and application updates to versions that contain fixes for the JavaScript engine memory corruption issues. Organizations should prioritize updating all affected Mozilla applications including Firefox, Thunderbird, and SeaMonkey to their patched versions, as these updates contain memory safety improvements and proper input validation for string operations. Additional defensive measures include implementing strict web content filtering, deploying sandboxing technologies to limit the impact of potential exploitation, and utilizing security modules that can detect and block suspicious JavaScript behavior. Network-level protections such as web application firewalls and intrusion detection systems can help identify and prevent exploitation attempts. The vulnerability also highlights the importance of maintaining up-to-date security patches across all browser applications and implementing security awareness training for users to recognize potentially malicious web content. Organizations should also consider implementing browser hardening configurations that disable unnecessary JavaScript features and restrict access to potentially dangerous APIs that could be exploited through similar memory corruption vulnerabilities.