CVE-2009-0357 in Firefox
Summary
by MITRE
Mozilla Firefox before 3.0.6 and SeaMonkey before 1.1.15 do not properly restrict access from web pages to the (1) Set-Cookie and (2) Set-Cookie2 HTTP response headers, which allows remote attackers to obtain sensitive information from cookies via XMLHttpRequest calls, related to the HTTPOnly protection mechanism.
Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.
Analysis
by VulDB Data Team • 08/26/2019
This vulnerability resides in the fundamental security architecture of web browsers, specifically targeting the implementation of HttpOnly cookie protection mechanisms within Mozilla Firefox and SeaMonkey browsers. The flaw represents a critical failure in cross-origin resource access controls that undermines the core security principle designed to prevent client-side script access to sensitive cookie data. When browsers properly implement HttpOnly flags, they should prevent JavaScript execution contexts from accessing cookies that have been marked with this security attribute, thereby mitigating cross-site scripting attacks that attempt to steal session tokens and other sensitive authentication data.
The technical implementation defect occurs in how these browsers handle XMLHttpRequest objects when processing HTTP response headers containing Set-Cookie and Set-Cookie2 directives. The vulnerability stems from insufficient validation mechanisms that should prevent web pages from accessing these specific response headers through programmatic interfaces. This allows malicious web pages to extract cookie values that would normally be protected from JavaScript access, effectively bypassing the HttpOnly protection that was designed to shield against cookie theft through XSS attacks. The flaw specifically affects versions prior to Firefox 3.0.6 and SeaMonkey 1.1.15, indicating that these browser versions contained incomplete or improperly implemented security controls for handling HTTP response headers.
The operational impact of this vulnerability is severe and directly enables credential theft attacks that can compromise user sessions and sensitive data. Attackers can leverage this weakness to harvest authentication cookies from legitimate web applications, potentially gaining unauthorized access to user accounts and sensitive information without requiring additional exploitation techniques. This vulnerability particularly affects web applications that rely on cookie-based authentication mechanisms, as it allows attackers to bypass the intended security boundaries that separate sensitive cookie data from client-side script execution contexts. The implications extend beyond simple session hijacking to include potential data breaches and unauthorized access to protected resources.
Security researchers have classified this vulnerability under CWE-116, which addresses improper encoding or escaping of output, and it aligns with ATT&CK technique T1566, specifically targeting credential access through web application vulnerabilities. The vulnerability demonstrates a critical flaw in browser security model implementation where the boundary between secure and insecure cookie access has been improperly enforced. Organizations and users must understand that this vulnerability represents a fundamental breakdown in the browser's security architecture, requiring immediate patching of affected browser versions to restore proper HttpOnly protection mechanisms.
The remediation strategy involves updating to patched versions of Firefox and SeaMonkey where the HTTP response header access controls have been properly implemented. Security administrators should prioritize patch deployment across all affected systems and conduct thorough testing to ensure that the updated browsers correctly enforce HttpOnly protections. Additionally, organizations should implement comprehensive monitoring for suspicious cookie access patterns and consider additional security measures such as secure cookie attributes, proper CORS policies, and enhanced web application security controls to mitigate potential exploitation of similar vulnerabilities in other components of their security infrastructure.