What’s Vulnerable › Vulnerabilities

CVE-2020-8159

• Severity: critical (CVSS 9.8 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 5.4% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2020-05-12 · updated 2026-06-17
• Weakness: CWE-22

Description

There is a vulnerability in actionpack_page-caching gem < v1.2.1 that allows an attacker to write arbitrary files to a web server, potentially resulting in remote code execution if the attacker can write unescaped ERB to a view.

Affected products

• Debian Linux: 9.0
• rubyonrails Actionpack Page-Caching: before 1.2.1 — fixed in 1.2.1

How to fix

Upgrade to a fixed version: rubyonrails Actionpack Page-Caching 1.2.1. Check the vendor advisory for mitigations.

References

• https://groups.google.com/forum/#%21topic/rubyonrails-security/CFRVkEytdP8
• https://lists.debian.org/debian-lts-announce/2021/07/msg00019.html
• https://groups.google.com/forum/#%21topic/rubyonrails-security/CFRVkEytdP8
• https://lists.debian.org/debian-lts-announce/2021/07/msg00019.html

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