Document disclosure and substitution via CRC32 collisions
Published Jul 27, 2021 · Updated Aug 3, 2024
Improper access control in Open-Xchange OX Documents before 7.10.5-rev7 allows remote authenticated users to read or substitute converted content. The documentconverter caches rendered documents under CRC32-derived keys, so two uploaded files with the same checksum resolve to one cached conversion. Access to document conversion and a deliberately colliding upload are required; a successful collision serves one document's content when another is viewed, causing disclosure or unauthorized substitution.
Summary
What happened
Improper access control in Open-Xchange OX Documents before 7.10.5-rev7 allows remote authenticated users to read or substitute converted content. The documentconverter caches rendered documents under CRC32-derived keys, so two uploaded files with the same checksum resolve to one cached conversion. Access to document conversion and a deliberately colliding upload are required; a successful collision serves one document's content when another is viewed, causing disclosure or unauthorized substitution.
The record
- CVE
- CVE-2021-28094
- Published
- Jul 27, 2021
- Updated
- Aug 3, 2024
- Vendor
- Unknown vendor
- Product
- Unknown product
- Classifications
- CWE-326
- Attack vector
- network
- Privileges
- authenticated
Timeline
How it unfolded
- Jul 27, 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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Is a vulnerable build present?
What conditions does exploitation require?
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
- Open-Xchange collision reproduction procedureproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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