Content disclosure via cacheable error responses
Published Nov 15, 2021 · Updated Aug 4, 2024
Cache poisoning in Discourse before 2.7.10 and 2.8.0 through 2.8.0.beta7 allows remote attackers to expose content through cached errors. The anonymous-cache and public-exception middleware return 413 and invalid-MIME 400 responses without restrictive Cache-Control headers, allowing intermediaries to store them. Exploitation requires an intermediary proxy or misconfigured CDN to cache the crafted response; the documented consequence is confidentiality loss for some content.
Summary
What happened
Cache poisoning in Discourse before 2.7.10 and 2.8.0 through 2.8.0.beta7 allows remote attackers to expose content through cached errors. The anonymous-cache and public-exception middleware return 413 and invalid-MIME 400 responses without restrictive Cache-Control headers, allowing intermediaries to store them. Exploitation requires an intermediary proxy or misconfigured CDN to cache the crafted response; the documented consequence is confidentiality loss for some content.
The record
- CVE
- CVE-2021-41271
- Published
- Nov 15, 2021
- Updated
- Aug 4, 2024
- Vendor
- Discourse
- Product
- Discourse
- Classifications
- CWE-200, T1190
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Nov 15, 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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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=< 2.7.10
- Affected versionversion=>= 2.8.0, < 2.8.0.beta8
What conditions does exploitation require?
What is affected?
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
No public exploit references are available in this record.
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Technologies
Your stack
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Your stack
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