CVE-2021-3410
📋 TL;DR
This vulnerability is a buffer overflow in libcaca's caca_resize function that could allow local attackers to execute arbitrary code with the privileges of the user running the vulnerable application. It affects systems using libcaca v0.99.beta19 for ASCII art rendering. The impact is limited to local exploitation in user context.
💻 Affected Systems
- libcaca
📦 What is this software?
Fedora by Fedoraproject
Fedora by Fedoraproject
Libcaca by Libcaca Project
⚠️ Risk & Real-World Impact
Worst Case
Local privilege escalation leading to complete system compromise if exploited by a user with access to the vulnerable library.
Likely Case
Local code execution in user context, potentially allowing attackers to gain persistence or move laterally within the environment.
If Mitigated
Limited impact due to user-level privileges and local-only exploitation vector.
🎯 Exploit Status
Exploitation requires local access and knowledge of buffer overflow techniques. No public exploits were found in the provided references.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Fixed in later versions of libcaca (specific version not specified in references)
Vendor Advisory: https://bugzilla.redhat.com/show_bug.cgi?id=1928437
Restart Required: Yes
Instructions:
1. Update libcaca package using your distribution's package manager. 2. For Red Hat/Fedora: 'sudo dnf update libcaca'. 3. For Debian: 'sudo apt update && sudo apt upgrade libcaca'. 4. Restart any applications using libcaca.
🔧 Temporary Workarounds
Remove libcaca package
linuxUninstall libcaca if not required for system functionality
sudo dnf remove libcaca
sudo apt remove libcaca
Restrict user access
allLimit local user access to systems with vulnerable libcaca
🧯 If You Can't Patch
- Isolate affected systems from critical network segments
- Implement strict user access controls and monitor for suspicious activity
🔍 How to Verify
Check if Vulnerable:
Check libcaca version: 'rpm -q libcaca' (RHEL/Fedora) or 'dpkg -l | grep libcaca' (Debian/Ubuntu)Check Version:
rpm -q libcaca --queryformat '%{VERSION}' or dpkg -l libcaca | grep ^ii | awk '{print $3}'Verify Fix Applied:
Verify updated version is installed and no longer shows v0.99.beta19📡 Detection & Monitoring
Log Indicators:
- Segmentation faults in applications using libcaca
- Unusual process execution from libcaca-related processes
Network Indicators:
- Not applicable - local vulnerability
SIEM Query:
Process execution where parent process contains 'libcaca' or command line contains libcaca library calls🔗 References
- https://bugzilla.redhat.com/show_bug.cgi?id=1928437
- https://github.com/cacalabs/libcaca/issues/52
- https://lists.debian.org/debian-lts-announce/2021/03/msg00006.html
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/6WFGYICNTMNDNMDDUV4G2RYFB5HNJCOV/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/PC7EGOEQ5C4OD66ZUJJIIYEXBTZOCMZX/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ZSBCRN6EGQJUVOSD4OEEQ6XORHEM2CUL/
- https://bugzilla.redhat.com/show_bug.cgi?id=1928437
- https://github.com/cacalabs/libcaca/issues/52
- https://lists.debian.org/debian-lts-announce/2021/03/msg00006.html
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/6WFGYICNTMNDNMDDUV4G2RYFB5HNJCOV/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/PC7EGOEQ5C4OD66ZUJJIIYEXBTZOCMZX/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ZSBCRN6EGQJUVOSD4OEEQ6XORHEM2CUL/
