CVE-2010-2100 in PHP
Summary
by MITRE
The (1) htmlentities, (2) htmlspecialchars, (3) str_getcsv, (4) http_build_query, (5) strpbrk, and (6) strtr functions in PHP 5.2 through 5.2.13 and 5.3 through 5.3.2 allow context-dependent attackers to obtain sensitive information (memory contents) by causing a userspace interruption of an internal function, related to the call time pass by reference feature.
Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.
Analysis
by VulDB Data Team • 02/01/2025
The vulnerability identified as CVE-2010-2100 represents a critical information disclosure issue affecting multiple core PHP functions including htmlentities, htmlspecialchars, str_getcsv, http_build_query, strpbrk, and strtr. This flaw exists within PHP versions 5.2 through 5.2.13 and 5.3 through 5.3.2, specifically exploiting the interaction between these functions and the call time pass by reference feature. The vulnerability stems from improper handling of memory allocation during function execution when external interruptions occur, potentially allowing attackers to access sensitive memory contents that should remain protected.
The technical mechanism behind this vulnerability involves the exploitation of PHP's internal function execution flow when context-dependent attackers can interrupt the normal execution path of these functions. When these functions encounter certain conditions, particularly those involving the call time pass by reference feature, they may leave memory in an inconsistent state. This memory inconsistency can be leveraged by malicious actors to read adjacent memory locations, potentially exposing sensitive data such as passwords, session tokens, or other confidential information stored in memory. The vulnerability is classified under CWE-200 as "Information Exposure" and specifically relates to improper information handling during function execution.
The operational impact of this vulnerability is significant as it allows remote attackers to potentially extract sensitive information from the memory space of PHP processes. Attackers can exploit this weakness by crafting specific inputs that cause the targeted functions to be interrupted during execution, thereby exposing memory contents that would normally be protected. This information disclosure can lead to session hijacking, credential theft, or other attacks that leverage the leaked memory contents to escalate privileges or gain unauthorized access to systems. The vulnerability is particularly dangerous because it affects fundamental PHP functions that are widely used across web applications, making it a prime target for exploitation.
Mitigation strategies for CVE-2010-2100 primarily involve upgrading to patched versions of PHP where this vulnerability has been resolved. Organizations should immediately upgrade to PHP 5.2.14 or 5.3.3 or later versions that contain the necessary fixes for this memory exposure issue. Additionally, implementing proper input validation and sanitization practices can help reduce the attack surface, though this does not fully address the underlying vulnerability. Security monitoring should include detection of unusual memory access patterns and potential exploitation attempts targeting these specific PHP functions. The ATT&CK framework categorizes this vulnerability under T1005 "Data from Local System" and T1059 "Command and Scripting Interpreter" as attackers may use the leaked information to perform further exploitation or establish persistence within affected systems.