CVE-2021-26926
📋 TL;DR
CVE-2021-26926 is an out-of-bounds read vulnerability in Jasper's jp2_decode function that could allow attackers to read sensitive memory contents or cause denial of service through application crashes. This affects systems using Jasper library versions before 2.0.25 for processing JPEG 2000 images. Any application that uses Jasper to parse untrusted JPEG 2000 files is potentially vulnerable.
💻 Affected Systems
- Jasper JPEG 2000 library
- Applications using Jasper library
📦 What is this software?
Fedora by Fedoraproject
Fedora by Fedoraproject
Fedora by Fedoraproject
Jasper by Jasper Project
⚠️ Risk & Real-World Impact
Worst Case
Information disclosure of sensitive memory contents, potentially including credentials, keys, or other application data, leading to complete system compromise.
Likely Case
Application crash causing denial of service, with possible limited information disclosure from memory reads.
If Mitigated
No impact if proper input validation and memory protections are in place, or if untrusted JPEG 2000 files are not processed.
🎯 Exploit Status
Exploitation requires crafting a malicious JPEG 2000 file that triggers the out-of-bounds read. Public proof-of-concept exists in GitHub issues.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 2.0.25 and later
Vendor Advisory: https://github.com/jasper-software/jasper/commit/41f214b121b837fa30d9ca5f2430212110f5cd9b
Restart Required: Yes
Instructions:
1. Update Jasper to version 2.0.25 or later. 2. Recompile applications using Jasper. 3. Restart affected services. 4. For Linux distributions, use package manager: 'sudo apt update && sudo apt upgrade jasper' (Debian/Ubuntu) or 'sudo yum update jasper' (RHEL/CentOS).
🔧 Temporary Workarounds
Disable JPEG 2000 processing
allConfigure applications to reject or not process JPEG 2000 files if not required.
Application-specific configuration required
Input validation and sanitization
allImplement strict validation of JPEG 2000 files before processing.
Implement file signature validation and size limits
🧯 If You Can't Patch
- Implement network segmentation to isolate vulnerable systems
- Deploy application-level firewalls to block malicious JPEG 2000 files
🔍 How to Verify
Check if Vulnerable:
Check Jasper version: 'jasper --version' or check linked library version in applications.Check Version:
jasper --version 2>&1 | head -1Verify Fix Applied:
Verify version is 2.0.25 or later: 'jasper --version' should show 2.0.25+.📡 Detection & Monitoring
Log Indicators:
- Application crashes when processing JPEG 2000 files
- Memory access violation errors
- Segmentation faults in Jasper-related processes
Network Indicators:
- Unusual JPEG 2000 file uploads to web applications
- Multiple failed parsing attempts
SIEM Query:
source="application.logs" AND ("segmentation fault" OR "memory violation" OR "jasper") AND "jp2" OR "jpeg2000"🔗 References
- https://github.com/jasper-software/jasper/commit/41f214b121b837fa30d9ca5f2430212110f5cd9b
- https://github.com/jasper-software/jasper/issues/264
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/JSXESYUHMO522Z3RHXOQ2SJNWP3XTO67/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/JYVCFVTVPL66OS7LCNLUSYCMYQAVWXMM/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/YRZFZSJ4UVLLMXSKHR455TAC2SD3TOHI/
- https://github.com/jasper-software/jasper/commit/41f214b121b837fa30d9ca5f2430212110f5cd9b
- https://github.com/jasper-software/jasper/issues/264
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/JSXESYUHMO522Z3RHXOQ2SJNWP3XTO67/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/JYVCFVTVPL66OS7LCNLUSYCMYQAVWXMM/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/YRZFZSJ4UVLLMXSKHR455TAC2SD3TOHI/
