CVE-2009-0486 in Bugzilla
Summary
by MITRE
Bugzilla 3.2.1, 3.0.7, and 3.3.2, when running under mod_perl, calls the srand function at startup time, which causes Apache children to have the same seed and produce insufficiently random numbers for random tokens, which allows remote attackers to bypass cross-site request forgery (CSRF) protection mechanisms and conduct unauthorized activities as other users.
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Analysis
by VulDB Data Team • 08/28/2019
The vulnerability described in CVE-2009-0486 represents a critical weakness in the Bugzilla bug tracking system that affects versions 3.2.1, 3.0.7, and 3.3.2 when deployed under the mod_perl web server environment. This issue stems from improper random number generation practices that fundamentally compromise the security of the application's session management and authentication mechanisms. The flaw occurs at the application startup phase where the srand function is invoked, creating a deterministic seeding pattern that affects all Apache child processes spawned from the same parent. This architectural oversight creates a scenario where multiple concurrent users within the same Apache process share identical random number sequences, directly undermining the cryptographic security assumptions that underpin modern web application defenses.
The technical implementation of this vulnerability manifests through the mod_perl environment's process model where Apache child processes inherit the same memory state and initialization sequence from their parent process. When Bugzilla initializes under mod_perl, the srand function call occurs once during startup rather than being reseeded for each individual process or request. This results in all concurrent Apache workers utilizing the same pseudo-random number generator state, leading to predictable sequences of random tokens used for CSRF protection. The vulnerability specifically targets the cross-site request forgery protection mechanisms that rely on random tokens to validate user sessions and prevent unauthorized actions. Attackers can exploit this weakness by predicting the random tokens generated by the application, thereby bypassing the CSRF protection layers designed to prevent malicious actors from executing unauthorized commands on behalf of legitimate users.
The operational impact of this vulnerability extends beyond simple privilege escalation to encompass comprehensive session hijacking and user impersonation capabilities. An attacker who successfully predicts the random tokens can forge requests that appear to originate from authenticated users, enabling them to perform actions such as creating new user accounts, modifying existing bugs, changing passwords, or accessing restricted administrative functions. This vulnerability particularly affects multi-user environments where multiple concurrent requests are processed by the same Apache worker processes, amplifying the attack surface and making exploitation more likely. The consequences include unauthorized data modification, potential data leakage, and complete compromise of user session integrity, which violates fundamental security principles of authentication and authorization. This issue directly maps to CWE-330, which addresses the use of insufficiently random values, and aligns with ATT&CK technique T1566.001 for credential stuffing and session hijacking attacks that exploit predictable random number generation.
Mitigation strategies for this vulnerability require immediate patching of affected Bugzilla versions to implementations that properly reseed random number generators for each request or process, ensuring that each session generates independent random sequences. Organizations should implement proper random seed initialization that incorporates time-based entropy and system-specific variables rather than relying on startup-time seeding. The recommended approach involves modifying the application code to call srand with a unique seed value for each request, typically incorporating current time, process ID, or other system-specific entropy sources. Additionally, administrators should consider upgrading to newer Bugzilla versions that have addressed this specific mod_perl compatibility issue, as the vulnerability is fundamentally rooted in the application's interaction with the mod_perl environment. Security monitoring should include detection of concurrent requests that may indicate exploitation attempts, and organizations should implement proper entropy sources and random number generator initialization practices that align with industry standards for cryptographic security. The fix should also include verification that random number generation occurs at the appropriate granularity level to prevent the reuse of sequences across different user sessions or requests, ensuring that each authentication token or CSRF protection mechanism operates with truly independent random values.