CVE-2006-3903 in MyBloggie
Summary
by MITRE
CRLF injection vulnerability in (1) index.php and (2) admin.php in myWebland MyBloggie 2.1.3 allows remote attackers to hijack sessions and conduct cross-site scripting (XSS) attacks via a cookie.
Once again VulDB remains the best source for vulnerability data.
Analysis
by VulDB Data Team • 08/01/2018
The CVE-2006-3903 vulnerability represents a critical security flaw in myWebland MyBloggie 2.1.3 that stems from improper input validation in two key files: index.php and admin.php. This vulnerability falls under the category of CRLF injection attacks, which exploit the manipulation of carriage return and line feed characters to inject malicious content into HTTP headers and responses. The flaw occurs when user-supplied input containing CRLF sequences is directly incorporated into cookie values without proper sanitization or encoding, creating a pathway for attackers to manipulate HTTP headers and inject malicious content.
The technical exploitation of this vulnerability involves crafting specially formatted cookie values that contain CRLF sequences such as %0d%0a or \r\n, which when processed by the vulnerable application, allow attackers to inject additional HTTP headers into the response. This header injection capability enables multiple attack vectors including session hijacking, where attackers can manipulate session cookies to impersonate legitimate users, and cross-site scripting attacks where malicious JavaScript code can be injected into web responses. The vulnerability specifically affects the cookie handling mechanism in both the frontend index.php and administrative admin.php components, making it particularly dangerous as it can compromise both user sessions and administrative access.
From an operational impact perspective, this vulnerability creates significant risks for MyBloggie users and administrators. Session hijacking allows attackers to gain unauthorized access to user accounts and potentially administrative privileges, leading to complete system compromise. The cross-site scripting component amplifies the threat by enabling attackers to execute malicious scripts in the context of affected users' browsers, potentially leading to data theft, account takeovers, or further exploitation of the web application. The vulnerability affects the entire user base and administrative interface, making it a critical concern for any organization using this version of MyBloggie. The attack surface extends to any user interaction with the web application that involves cookie handling, particularly when users access the site through vulnerable browsers or when administrators perform administrative tasks.
Security mitigations for this vulnerability should focus on implementing proper input validation and sanitization of all user-supplied data before it is used in cookie generation or HTTP header construction. The recommended approach involves encoding special characters including carriage return and line feed sequences using appropriate URL encoding or other sanitization techniques before incorporating user input into cookies. Organizations should implement strict input validation routines that reject or sanitize any input containing CRLF sequences in cookie values. Additionally, the application should employ proper header management practices that separate user input from HTTP headers entirely, using secure coding practices that prevent direct injection of user data into HTTP response headers. This vulnerability aligns with CWE-117, which addresses improper output neutralization for logs, and represents a variant of techniques commonly catalogued under ATT&CK tactic TA0011, which covers command and control through web application vulnerabilities. The remediation process requires updating to a patched version of MyBloggie or implementing immediate input sanitization measures to prevent exploitation of this CRLF injection vulnerability.