CVE-2022-22817
📋 TL;DR
CVE-2022-22817 is a critical vulnerability in Pillow's ImageMath.eval function that allows arbitrary Python code execution through expression evaluation. This affects applications using Pillow for image processing that pass user-controlled input to ImageMath.eval. Attackers can execute arbitrary commands on the system with the privileges of the application.
💻 Affected Systems
- Pillow (Python Imaging Library fork)
📦 What is this software?
Pillow by Python
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution leading to complete system compromise, data theft, ransomware deployment, or lateral movement within the network.
Likely Case
Application compromise allowing data exfiltration, credential theft, or serving as an initial foothold for further attacks.
If Mitigated
Limited impact if proper input validation and sandboxing are implemented, potentially resulting in application crash or denial of service.
🎯 Exploit Status
Exploitation is straightforward - attackers can craft malicious expressions using Python exec or lambda functions. No authentication required if the vulnerable endpoint is exposed.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 9.0.0 and later
Vendor Advisory: https://pillow.readthedocs.io/en/stable/releasenotes/9.0.0.html#restrict-builtins-available-to-imagemath-eval
Restart Required: No
Instructions:
1. Update Pillow to version 9.0.0 or later using pip: pip install --upgrade Pillow>=9.0.0
2. Verify the update with: pip show Pillow
3. Test application functionality after update.
🔧 Temporary Workarounds
Disable ImageMath.eval usage
allRemove or disable usage of ImageMath.eval function in application code if not essential.
# Review code for ImageMath.eval usage and replace with safer alternatives
Input validation and sanitization
allImplement strict input validation for any data passed to ImageMath.eval.
# Validate and sanitize all user input before passing to ImageMath.eval
🧯 If You Can't Patch
- Implement network segmentation to isolate vulnerable systems from critical assets
- Deploy application-level firewalls (WAF) to block malicious payloads targeting ImageMath.eval
🔍 How to Verify
Check if Vulnerable:
Check Pillow version with: python -c "import PIL; print(PIL.__version__)" or pip show Pillow. Versions below 9.0.0 are vulnerable.Check Version:
python -c "import PIL; print(PIL.__version__)" or pip show Pillow | grep VersionVerify Fix Applied:
Confirm Pillow version is 9.0.0 or higher: python -c "import PIL; print(PIL.__version__)"📡 Detection & Monitoring
Log Indicators:
- Unusual Python execution errors
- Suspicious import statements in application logs
- Unexpected subprocess executions from Python processes
Network Indicators:
- Outbound connections from application servers to unknown destinations
- Unusual data exfiltration patterns
SIEM Query:
source="application.logs" AND ("ImageMath.eval" OR "exec(" OR "lambda") AND severity=HIGH🔗 References
- https://lists.debian.org/debian-lts-announce/2022/01/msg00018.html
- https://lists.debian.org/debian-lts-announce/2024/03/msg00021.html
- https://pillow.readthedocs.io/en/stable/releasenotes/9.0.0.html#restrict-builtins-available-to-imagemath-eval
- https://pillow.readthedocs.io/en/stable/releasenotes/9.0.1.html#security
- https://security.gentoo.org/glsa/202211-10
- https://www.debian.org/security/2022/dsa-5053
- https://lists.debian.org/debian-lts-announce/2022/01/msg00018.html
- https://lists.debian.org/debian-lts-announce/2024/03/msg00021.html
- https://pillow.readthedocs.io/en/stable/releasenotes/9.0.0.html#restrict-builtins-available-to-imagemath-eval
- https://pillow.readthedocs.io/en/stable/releasenotes/9.0.1.html#security
- https://security.gentoo.org/glsa/202211-10
- https://www.debian.org/security/2022/dsa-5053
