CVE-2008-2829 in PHP
Summary
by MITRE
php_imap.c in PHP 5.2.5, 5.2.6, 4.x, and other versions, uses obsolete API calls that allow context-dependent attackers to cause a denial of service (crash) and possibly execute arbitrary code via a long IMAP request, which triggers an "rfc822.c legacy routine buffer overflow" error message, related to the rfc822_write_address function.
If you want to get best quality of vulnerability data, you may have to visit VulDB.
Analysis
by VulDB Data Team • 08/01/2021
The vulnerability described in CVE-2008-2829 represents a critical security flaw within PHP's IMAP extension that affects multiple versions including 5.2.5, 5.2.6, and 4.x series. This issue stems from the use of deprecated API calls within the php_imap.c file, creating a pathway for malicious actors to exploit buffer overflow conditions during IMAP request processing. The vulnerability specifically targets the rfc822.c legacy routine which handles email address formatting and parsing operations, making it particularly dangerous in web applications that process email data through PHP's IMAP functionality.
The technical exploitation of this vulnerability occurs when an attacker submits a specially crafted, exceptionally long IMAP request to a PHP application that utilizes the imap_open() or similar IMAP functions. The underlying rfc822_write_address function processes this malformed input through obsolete code paths that lack proper bounds checking, leading to buffer overflow conditions in the legacy rfc822.c routines. This buffer overflow manifests as a crash or potential code execution, depending on the specific conditions and system configuration. The vulnerability is classified as context-dependent because it requires specific environmental conditions to be exploited successfully, particularly the presence of PHP applications that handle IMAP requests with insufficient input validation.
From an operational standpoint, this vulnerability poses significant risks to web applications that rely on PHP's IMAP capabilities for email processing, mail server integration, or email-based authentication systems. Attackers can leverage this flaw to cause denial of service conditions that take down web applications or entire servers, disrupting business operations and potentially leading to data loss or service unavailability. The potential for arbitrary code execution adds an additional layer of severity, as successful exploitation could allow attackers to gain unauthorized access to server resources, execute malicious commands, or establish persistent backdoors. This makes the vulnerability particularly attractive to threat actors targeting web infrastructure and email-based applications.
Organizations affected by this vulnerability should prioritize immediate patching of their PHP installations to versions that contain fixes for the buffer overflow conditions in the IMAP extension. System administrators should also implement input validation measures to prevent excessively long IMAP requests from reaching the vulnerable code paths, though this represents a partial mitigation rather than a complete solution. The vulnerability aligns with CWE-121, Buffer Overflow in Non-Stack Data, and demonstrates characteristics consistent with ATT&CK technique T1190, Exploit Public-Facing Application, as it targets publicly accessible web applications that process email data. Network segmentation and monitoring for unusual IMAP request patterns can help detect potential exploitation attempts, while regular security assessments should verify that all PHP components are updated to secure versions that eliminate these legacy API dependencies.