Undefined behavior via unbounded posterization values
Published May 14, 2021 · Updated Aug 4, 2024
Undefined behavior in ImageMagick before 7.0.9-0 allows attackers to trigger invalid float conversions through a crafted PDF file. In PosterizeImage, posterization arithmetic casts unbounded pixel results directly to Quantum values; the patch instead clamps those results and bounds intensity comparisons to the integer range. An operator or integrating application must process attacker-supplied content with the crafted transformation parameters, and Red Hat reported no demonstrated impact beyond the undefined behavior and an availability risk.
Summary
What happened
Undefined behavior in ImageMagick before 7.0.9-0 allows attackers to trigger invalid float conversions through a crafted PDF file. In PosterizeImage, posterization arithmetic casts unbounded pixel results directly to Quantum values; the patch instead clamps those results and bounds intensity comparisons to the integer range. An operator or integrating application must process attacker-supplied content with the crafted transformation parameters, and Red Hat reported no demonstrated impact beyond the undefined behavior and an availability risk.
The record
- CVE
- CVE-2020-27769
- Published
- May 14, 2021
- Updated
- Aug 4, 2024
- Vendor
- ImageMagick Studio LLC
- Product
- ImageMagick
- Classifications
- CWE-190, T1204.002
- Attack vector
- local
- Privileges
- unauthenticated
Timeline
How it unfolded
- May 14, 2021CVE publishedPublication date reported by the CVE source.
- Aug 4, 2024Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
Compare your product and version with the public record. A matching version still requires validation against your environment.
Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=ImageMagick versions before 7.0.9-0
What conditions does exploitation require?
What is affected?
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- ImageMagick issue 1740 reproducerproof of concept · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
See the directory against your own environment.
Your stack
Check the software in your environment
Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.
Book a demo