Encoder crash via zero APNG delay denominator
Published Aug 30, 2021 · Updated Aug 4, 2024
Divide-by-zero in libjxl 0.3.7 allows context-dependent attackers to crash cjxl by supplying a crafted APNG image for encoding. DecodeImageAPNG accepts a zero delay_den value from the APNG frame-control chunk and uses it as a divisor instead of applying the default value of 100. The image must be processed by cjxl; the resulting floating-point exception terminates that encoding process without reported data disclosure or modification.
Summary
What happened
Divide-by-zero in libjxl 0.3.7 allows context-dependent attackers to crash cjxl by supplying a crafted APNG image for encoding. DecodeImageAPNG accepts a zero delay_den value from the APNG frame-control chunk and uses it as a divisor instead of applying the default value of 100. The image must be processed by cjxl; the resulting floating-point exception terminates that encoding process without reported data disclosure or modification.
The record
- CVE
- CVE-2021-36692
- Published
- Aug 30, 2021
- Updated
- Aug 4, 2024
- Vendor
- Unknown vendor
- Product
- Unknown product
- Classifications
- CWE-369, T1204.003
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Aug 30, 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
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What is affected?
Affected products and versions are unavailable in this record.
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.
Public exploit references
- Issue 308 crash.png proof of conceptproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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