CVE-2011-3626 in Logsurfer
Summary
by MITRE
Double free vulnerability in the prepare_exec function in src/exec.c in Logsurfer 1.5b and earlier, and Logsurfer+ 1.7 and earlier, allows remote attackers to execute arbitrary commands via crafted strings in a log file.
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Analysis
by VulDB Data Team • 11/29/2021
The CVE-2011-3626 vulnerability represents a critical double free memory corruption flaw in the logsurfer and logsurfer+ log monitoring utilities. This vulnerability exists within the prepare_exec function located in the src/exec.c source file of affected versions. The flaw manifests when the application processes log file entries containing specially crafted strings that trigger improper memory management during command execution preparation. The double free condition occurs when the same memory block is freed twice, creating a state where subsequent memory operations can corrupt the heap structure and potentially allow arbitrary code execution.
The technical exploitation of this vulnerability leverages the fundamental weakness in memory management where the prepare_exec function fails to properly validate or sanitize input strings before processing them for command execution. When a remote attacker crafts malicious log entries containing specific sequences that cause the function to attempt freeing the same memory location twice, the heap corruption creates opportunities for code execution. This type of vulnerability falls under the CWE-459 category of incomplete cleanup, specifically CWE-459 incomplete cleanup, which is closely related to memory management errors that can lead to heap corruption and arbitrary code execution. The vulnerability is particularly dangerous because it allows remote code execution through log file manipulation, making it a significant threat to systems that process untrusted log data.
The operational impact of CVE-2011-3626 extends beyond simple privilege escalation as it enables remote attackers to gain full control over affected systems through log file manipulation. Systems running vulnerable versions of logsurfer or logsurfer+ are at risk when processing log files from untrusted sources, including network logs, application logs, or any external log data feeds. The attack vector is particularly concerning because it requires minimal privileges to exploit and can be executed without direct network access to the target system. The vulnerability is consistent with ATT&CK technique T1059.007 for command and scripting interpreter, where attackers can leverage legitimate system tools to execute malicious code, and T1078.004 for valid accounts, as the exploitation can occur through legitimate log processing mechanisms.
Mitigation strategies for CVE-2011-3626 should prioritize immediate patching of affected systems to versions that address the double free condition in the prepare_exec function. Organizations should implement strict input validation and sanitization for all log file processing, particularly for systems that process external or untrusted log data sources. Network segmentation and access controls should limit the ability of remote attackers to manipulate log files that could trigger the vulnerability. The implementation of monitoring and alerting for unusual log file processing patterns can help detect potential exploitation attempts. Additionally, organizations should consider implementing application whitelisting to restrict which log processing tools can execute commands, and establish robust log integrity verification mechanisms to prevent the injection of malicious content into log files. Security teams should also conduct regular vulnerability assessments to identify and remediate similar memory corruption issues in other system components, as this vulnerability demonstrates the importance of proper memory management in security-critical applications. The fix for this vulnerability typically involves implementing proper memory allocation and deallocation patterns that prevent the same memory block from being freed multiple times, ensuring that all pointers are properly cleared after deallocation to prevent reuse.