CVE-2023-4736
📋 TL;DR
CVE-2023-4736 is an untrusted search path vulnerability in Vim that allows attackers to execute arbitrary code by placing malicious files in directories that Vim searches. This affects users running vulnerable Vim versions on systems where untrusted directories are in the search path. The vulnerability stems from improper handling of dynamic library loading paths.
💻 Affected Systems
- Vim
📦 What is this software?
Macos by Apple
macOS is Apple's desktop and laptop operating system powering Mac computers used by millions of professionals, developers, creative professionals, and enterprise users worldwide. Built on a Unix foundation with the Darwin kernel and modern Cocoa frameworks, macOS delivers a seamless ecosystem integr...
Learn more about Macos →Vim by Vim
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution with the privileges of the Vim user, potentially leading to full system compromise if the user has elevated privileges.
Likely Case
Local privilege escalation or arbitrary code execution when users open files from untrusted directories or when attackers can place files in writable directories.
If Mitigated
Limited impact if proper file permissions restrict write access to system directories and users avoid opening files from untrusted sources.
🎯 Exploit Status
Exploitation requires the attacker to place malicious files in directories that Vim searches, which typically requires some level of access or social engineering.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 9.0.1833 and later
Vendor Advisory: https://github.com/vim/vim/commit/816fbcc262687b81fc46f82f7bbeb1453addfe0c
Restart Required: No
Instructions:
1. Update Vim using your system package manager (apt-get upgrade vim, yum update vim, etc.) 2. Alternatively, compile from source using the patched version from the official Vim repository 3. Verify the version is 9.0.1833 or higher
🔧 Temporary Workarounds
Restrict library search paths
linuxModify environment variables to restrict where Vim searches for dynamic libraries
export LD_LIBRARY_PATH=/usr/lib:/usr/local/lib
export DYLD_LIBRARY_PATH=/usr/lib:/usr/local/lib
Avoid untrusted directories
allDo not run Vim from or open files in directories with untrusted write access
🧯 If You Can't Patch
- Restrict file permissions to prevent untrusted users from writing to directories in Vim's search path
- Use alternative text editors until patching is possible
🔍 How to Verify
Check if Vulnerable:
Check Vim version with 'vim --version' and look for version number lower than 9.0.1833Check Version:
vim --version | head -1Verify Fix Applied:
Run 'vim --version' and confirm version is 9.0.1833 or higher📡 Detection & Monitoring
Log Indicators:
- Unusual library loading from non-standard directories
- Failed attempts to load malicious libraries
Network Indicators:
- No direct network indicators as this is a local vulnerability
SIEM Query:
Process execution logs showing vim loading libraries from unusual paths or user home directories🔗 References
- http://seclists.org/fulldisclosure/2023/Oct/24
- https://github.com/vim/vim/commit/816fbcc262687b81fc46f82f7bbeb1453addfe0c
- https://huntr.dev/bounties/e1ce0995-4df4-4dec-9cd7-3136ac3e8e71
- https://support.apple.com/kb/HT213984
- http://seclists.org/fulldisclosure/2023/Oct/24
- https://github.com/vim/vim/commit/816fbcc262687b81fc46f82f7bbeb1453addfe0c
- https://huntr.dev/bounties/e1ce0995-4df4-4dec-9cd7-3136ac3e8e71
- https://support.apple.com/kb/HT213984
