CVE-2012-2104 in munin
Summary
by MITRE
cgi-bin/munin-cgi-graph in Munin 2.x writes data to a log file without sanitizing non-printable characters, which might allow user-assisted remote attackers to inject terminal emulator escape sequences and execute arbitrary commands or delete arbitrary files via a crafted HTTP request.
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Analysis
by VulDB Data Team • 07/07/2024
The vulnerability identified as CVE-2012-2104 affects the munin-cgi-graph component within Munin version 2.x monitoring systems. This flaw exists in the cgi-bin directory where the munin-cgi-graph script processes incoming HTTP requests and generates graph data for display. The issue stems from inadequate input validation and sanitization of user-supplied data that flows into log file operations. When the script handles HTTP requests containing specially crafted parameters, it fails to properly sanitize non-printable characters that may be present in the request data. This oversight creates a path for malicious actors to inject terminal escape sequences directly into the logging mechanism, potentially allowing for command execution or file manipulation on the affected system.
The technical exploitation of this vulnerability relies on the principle of terminal escape sequence injection, which is a well-documented attack vector that has been classified under CWE-77 and CWE-78 in the Common Weakness Enumeration catalog. The flaw specifically manifests when the munin-cgi-graph script writes user-controllable data to log files without proper sanitization, creating an environment where attackers can manipulate terminal control sequences. These escape sequences, when interpreted by terminal emulators or log viewers, can trigger unintended behavior such as command execution, file deletion, or privilege escalation. The vulnerability is classified as user-assisted remote exploitation because it requires a crafted HTTP request from an attacker, but once executed, it can potentially provide unauthorized access to system resources. The attack vector leverages the combination of improper input handling and log file processing to create a command injection scenario that operates outside the normal application boundaries.
The operational impact of CVE-2012-2104 extends beyond simple data corruption or unauthorized access, as it can potentially lead to complete system compromise when exploited by skilled attackers. The vulnerability affects systems running Munin monitoring software, which is commonly deployed in network infrastructure monitoring environments where administrative privileges may be available. Attackers can leverage this weakness to execute arbitrary commands with the privileges of the web server process or the Munin user, potentially escalating to full system compromise. The log file writing operation provides an indirect execution path where the attacker's payload is not directly executed in the application context but rather interpreted by terminal emulators or log processing tools that read the maliciously crafted log entries. This characteristic makes the attack more subtle and harder to detect through traditional security monitoring approaches. Organizations using Munin for system monitoring are particularly vulnerable if they do not implement proper input validation or if they have web-accessible Munin installations that expose the affected cgi-bin components to untrusted users.
Mitigation strategies for CVE-2012-2104 should focus on input sanitization and proper log handling procedures. The primary remediation involves implementing strict sanitization of all user-supplied data before it is written to log files, particularly ensuring that non-printable characters and control sequences are removed or properly escaped. System administrators should apply the vendor-provided patches or upgrade to versions of Munin that address this vulnerability. Additionally, network segmentation and access controls should be implemented to limit exposure of the munin-cgi-graph component to untrusted networks. The implementation of proper logging practices, including the use of structured logging formats that do not rely on terminal control sequences, can prevent exploitation of this class of vulnerability. Organizations should also consider implementing web application firewalls or intrusion detection systems that can detect and block suspicious HTTP requests containing potentially malicious escape sequences. The ATT&CK framework categorizes this type of vulnerability under T1059 for command and scripting interpreter, as the exploitation leads to arbitrary command execution, and T1078 for valid accounts, since the attack may leverage existing system privileges. Regular security audits and code reviews should be conducted to identify similar input handling vulnerabilities in other monitoring or logging components within the infrastructure.