CVE-2022-27811
📋 TL;DR
CVE-2022-27811 is a critical OS command injection vulnerability in GNOME OCRFeeder that allows attackers to execute arbitrary commands on the system by crafting malicious PDF or image filenames containing shell metacharacters. This affects all users running OCRFeeder versions before 0.8.4 who process untrusted files. The vulnerability enables remote code execution with the privileges of the OCRFeeder process.
💻 Affected Systems
- GNOME OCRFeeder
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Full system compromise allowing attacker to execute arbitrary commands with the privileges of the OCRFeeder process, potentially leading to complete system takeover, data exfiltration, or lateral movement within the network.
Likely Case
Remote code execution allowing attackers to install malware, create backdoors, steal sensitive data, or use the compromised system as a foothold for further attacks.
If Mitigated
Limited impact if OCRFeeder runs with minimal privileges, in isolated environments, or only processes trusted files from controlled sources.
🎯 Exploit Status
Exploitation requires the attacker to supply a malicious filename, which could be delivered via email attachments, downloads, or network shares. The vulnerability is trivial to exploit once the malicious file reaches the vulnerable system.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 0.8.4 and later
Vendor Advisory: https://gitlab.gnome.org/GNOME/ocrfeeder/-/commit/5286120c8bc8b7ba74e0f9b19b5262b509f38cee
Restart Required: No
Instructions:
1. Update OCRFeeder to version 0.8.4 or later using your distribution's package manager. 2. For source installations: Download the latest release from GNOME GitLab, compile, and install. 3. Verify the update was successful by checking the version.
🔧 Temporary Workarounds
Restrict file processing
linuxOnly allow OCRFeeder to process files from trusted sources and sanitize filenames before processing.
Run with reduced privileges
linuxRun OCRFeeder with a non-privileged user account to limit potential damage from exploitation.
sudo -u lowprivilegeuser ocrfeeder
🧯 If You Can't Patch
- Disable OCRFeeder entirely if not essential for operations
- Implement strict input validation and filename sanitization before files reach OCRFeeder
🔍 How to Verify
Check if Vulnerable:
Check OCRFeeder version: ocrfeeder --version. If version is below 0.8.4, the system is vulnerable.Check Version:
ocrfeeder --versionVerify Fix Applied:
After updating, verify version is 0.8.4 or higher: ocrfeeder --version📡 Detection & Monitoring
Log Indicators:
- Unusual command execution from OCRFeeder process
- Suspicious filenames with shell metacharacters being processed
- Unexpected child processes spawned by OCRFeeder
Network Indicators:
- Outbound connections from OCRFeeder process to unexpected destinations
- Command and control traffic originating from systems running OCRFeeder
SIEM Query:
process_name="ocrfeeder" AND (process_command_line CONTAINS "bash" OR process_command_line CONTAINS "sh" OR process_command_line CONTAINS "$" OR process_command_line CONTAINS "`" OR process_command_line CONTAINS "|")🔗 References
- https://gitlab.gnome.org/GNOME/ocrfeeder/-/commit/5286120c8bc8b7ba74e0f9b19b5262b509f38cee
- https://gitlab.gnome.org/GNOME/ocrfeeder/-/issues/20
- https://gitlab.gnome.org/GNOME/ocrfeeder/-/merge_requests/13
- https://gitlab.gnome.org/GNOME/ocrfeeder/-/commit/5286120c8bc8b7ba74e0f9b19b5262b509f38cee
- https://gitlab.gnome.org/GNOME/ocrfeeder/-/issues/20
- https://gitlab.gnome.org/GNOME/ocrfeeder/-/merge_requests/13
