CVE-2026-85092 in LiME
Summary
by MITRE • 09/03/2026
LiME through 1.12.0 fails to validate the disk acquisition output path and does not use O_NOFOLLOW when opening the operator-supplied path parameter, allowing unprivileged local users to overwrite arbitrary root-owned files. An attacker who controls the output directory can create a symbolic link with the expected filename pointing to any root-owned file, and when the acquisition runs in kernel context, LiME follows the link and truncates the target file with the memory acquisition stream.
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Analysis
by VulDB Data Team • 09/03/2026
LiME is a widely used Linux Memory Extractor designed for forensic disk acquisition of volatile memory contents from running systems. The vulnerability identified in versions through 1.12.0 stems from insufficient validation of user-supplied input paths and improper handling of symbolic links during file operations. Specifically, the application fails to validate that the output path provided by the operator is a regular file rather than a symbolic link or directory. Furthermore, when opening this path for writing memory dumps, LiME does not utilize the O_NOFOLLOW flag in its system calls. This omission allows the kernel to follow symbolic links instead of treating them as errors, which creates a critical security flaw where an attacker can manipulate the destination of the write operation.
The technical mechanism of exploitation relies on privilege escalation through file manipulation. An unprivileged local user who has control over the directory intended for output creation can craft a malicious environment or argument set. By creating a symbolic link within that directory with the expected filename, but pointing it to an arbitrary root-owned file such as /etc/shadow or a binary in /usr/bin, the attacker sets a trap. When LiME executes its memory acquisition routine under kernel context, it opens the specified path for writing without checking if it is a symlink. Consequently, the system call follows the link and truncates the target root-owned file, overwriting its contents with the raw memory dump data generated by LiME. This results in arbitrary write privileges effectively granted to an unprivileged user via the elevated context of the forensic tool itself.
The operational impact of this vulnerability is severe, as it allows for complete compromise of system integrity and confidentiality. By overwriting critical root-owned files, an attacker can disrupt essential services, corrupt configuration data, or potentially inject malicious code if they control other aspects of the file content or subsequent execution flows. In forensic scenarios where LiME is used to preserve evidence, this flaw not only compromises the security posture but also invalidates the integrity of any acquired memory dumps, as the tool may have inadvertently destroyed critical system files during its operation. This represents a significant risk in environments where forensic tools are run with elevated privileges or by users who should not possess write access to sensitive system locations.
Mitigation strategies must address both immediate remediation and long-term defensive coding practices. The primary solution is to upgrade LiME to version 1.12.1 or later, where the developers have implemented proper validation checks for output paths and ensured that O_NOFOLLOW is used when opening files to prevent symlink following attacks. For systems running older versions, administrators should restrict write permissions on directories intended for forensic outputs so that only privileged users can create files within them. Additionally, security teams should enforce strict access controls around the execution of memory acquisition tools, ensuring they are run by trusted accounts with minimal necessary privileges where possible. Regular auditing of file system permissions and monitoring for unexpected modifications to root-owned files can also help detect such exploitation attempts in real time.
From a classification perspective, this vulnerability aligns with CWE-59: Improper Link Resolution Before File Access, which describes flaws related to symbolic link following that lead to unauthorized access or modification. It is also relevant to CWE-22: Improper Limitation of a Pathname to a Restricted Directory, as the failure to validate the output path allows writing outside intended boundaries if directory permissions are loose. In terms of attack vectors, this falls under ATT&CK technique T1074: Data Staged or Local Data Staging, where an attacker stages data in a location before moving it elsewhere, although here the staging is accidental due to symlink manipulation leading directly to destructive write operations. Understanding these classifications helps security professionals map similar vulnerabilities across other forensic and system administration tools that handle file paths without adequate sanitization.