CVE-2010-0825 in emacs
Summary
by MITRE
lib-src/movemail.c in movemail in emacs 22 and 23 allows local users to read, modify, or delete arbitrary mailbox files via a symlink attack, related to improper file-permission checks.
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Analysis
by VulDB Data Team • 05/05/2026
The vulnerability identified as CVE-2010-0825 resides within the movemail utility that is part of the GNU Emacs text editor suite, specifically in the lib-src/movemail.c source file. This flaw affects Emacs versions 22 and 23, creating a significant security risk for local users who can exploit improper file permission checks to manipulate mailbox files through symbolic link attacks. The movemail utility is designed to move mail from a remote mailbox to a local one, but it fails to properly validate file permissions when handling symbolic links, allowing malicious users to redirect file operations to unintended targets.
The technical implementation of this vulnerability stems from inadequate validation of file permissions and symbolic link resolution within the movemail utility. When movemail processes mailbox files, it does not properly verify whether the target files are symbolic links or whether the user has appropriate permissions to access the files they intend to modify. This weakness creates a race condition scenario where an attacker can create symbolic links that point to sensitive mailbox files, and when movemail executes, it follows these links and performs operations on the target files rather than the intended mailbox. The flaw is categorized under CWE-59 as Improper Link Resolution, specifically related to the manipulation of symbolic links during file operations.
The operational impact of this vulnerability is substantial for systems running affected Emacs versions, as it allows local users to escalate their privileges and access sensitive mailbox data. Attackers can leverage this vulnerability to read confidential email messages, modify existing mailbox contents, or completely delete mailbox files, potentially leading to data loss or information disclosure. The vulnerability particularly affects systems where multiple users share the same system and where Emacs is used for mail management. This issue aligns with ATT&CK technique T1068 which covers Local Privilege Escalation through exploitation of software vulnerabilities, and T1566 which covers the manipulation of file systems through symbolic links.
Mitigation strategies for this vulnerability include immediate patching of affected Emacs installations to versions that address the symbolic link handling issue. System administrators should ensure that all instances of Emacs 22 and 23 are upgraded to patched versions that properly validate file permissions and resolve symbolic links before performing file operations. Additionally, organizations should implement proper file permission controls and monitor for suspicious symbolic link creation in directories where mail operations occur. The vulnerability demonstrates the importance of proper input validation and file system security checks in utility programs that handle user data, particularly those operating in multi-user environments where privilege escalation risks are heightened. Regular security audits and vulnerability assessments should include checking for similar flaws in other utility programs that handle file operations and symbolic link resolution.