Service hang via zero-length FLI block advance
Published Jun 2, 2021 · Updated Aug 3, 2024
Denial of service in Pillow before 8.2.0 allows remote attackers to hang image-processing services by supplying crafted FLI data. FliDecode.c reads a block advance from the input and, before the correction, continued decoding when that value was zero, leaving the input pointer unchanged and causing an infinite loop. Exploitation requires an application to load attacker-controlled FLI data; the demonstrated consequence is a processing hang without reported data disclosure or modification.
Summary
What happened
Denial of service in Pillow before 8.2.0 allows remote attackers to hang image-processing services by supplying crafted FLI data. FliDecode.c reads a block advance from the input and, before the correction, continued decoding when that value was zero, leaving the input pointer unchanged and causing an infinite loop. Exploitation requires an application to load attacker-controlled FLI data; the demonstrated consequence is a processing hang without reported data disclosure or modification.
The record
- CVE
- CVE-2021-28676
- Published
- Jun 2, 2021
- Updated
- Aug 3, 2024
- Vendor
- Unknown vendor
- Product
- Unknown product
- Classifications
- CWE-835, T1499.004
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jun 2, 2021CVE publishedPublication date reported by the CVE source.
- Aug 3, 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.
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
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
- Pillow FLI timeout regression fixturesproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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