Remote code execution via unsafe cache unmarshalling
Published Jun 19, 2020 · Updated May 9, 2025
Deserialization of untrusted data in Ruby on Rails ActiveSupport before 5.2.4.3 or 6.0.3.1 allows remote attackers to execute code via crafted cache input. MemCacheStore and RedisCacheStore re-read values written with raw: true as Ruby Marshal objects instead of plain text, evaluating attacker-controlled data. Exploitation requires an application to cache remote-controlled input with raw: true and later read it inconsistently; affected applications can suffer object injection and potentially remote code execution.
Summary
What happened
Deserialization of untrusted data in Ruby on Rails ActiveSupport before 5.2.4.3 or 6.0.3.1 allows remote attackers to execute code via crafted cache input. MemCacheStore and RedisCacheStore re-read values written with raw: true as Ruby Marshal objects instead of plain text, evaluating attacker-controlled data. Exploitation requires an application to cache remote-controlled input with raw: true and later read it inconsistently; affected applications can suffer object injection and potentially remote code execution.
The record
- CVE
- CVE-2020-8165
- Published
- Jun 19, 2020
- Updated
- May 9, 2025
- Vendor
- Ruby on Rails
- Product
- Ruby on Rails
- Classifications
- CWE-502, T1190
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jun 19, 2020CVE publishedPublication date reported by the CVE source.
- May 9, 2025Record 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=Fixed in 5.2.4.3, 6.0.3.1
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
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Technologies
Your stack
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Your stack
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