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Fencer Vulns
critical 9.8

CVE-2020-8165 in the critical feed json

ActiveSupport potentially unintended unmarshalling of user-provided objects in MemCacheStore and RedisCacheStore

published 2020-05-26 6 y ago modified 2026-06-17 4 mo ago also GHSA-2p68-f74v-9wc6 , EUVD-2020-0401

cvss
9.8
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
45.7%
EPSS 45.7% chance of exploitation in 30 days, percentile 98%
public exploits
0
none known

Summary

A deserialization of untrusted data vulnernerability exists in rails < 5.2.4.3, rails < 6.0.3.1 that can allow an attacker to unmarshal user-provided objects in MemCacheStore and RedisCacheStore potentially resulting in an RCE.

Patch / fix

  • rubygems activesupport 5.2.4.3, 6.0.3.1
  • rubyonrails rails 5.2.4.3, 6.0.3.1
  • rails Debian 14, Debian 13, Debian 12 2:5.2.4.3+dfsg-1

debian advisories DEBIAN-CVE-2020-8165

  • tfm satellite capsule 6.9, satellite 6.9 6.1-4.el7sat
  • kobo satellite capsule 6.9, satellite 6.9 0.5.1-1.el7sat
  • pulp satellite capsule 6.9, satellite 6.9 2.21.5-2.el7sat
  • gofer satellite capsule 6.9, satellite 6.9 2.12.5-7.el7sat
  • future satellite capsule 6.9, satellite 6.9 0.16.0-11.el7sat
  • ostree satellite capsule 6.9, satellite 6.9 2017.1-2.atomic.el7
  • foreman satellite capsule 6.9, satellite 6.9 2.3.1.20-1.el7sat
  • katello satellite capsule 6.9, satellite 6.9 3.18.1-3.el7sat

red hat advisories RHSA-2021:1313

  • rmt-server SLE Module for Server Applications 15 SP1, SLE Module for Public Cloud 15 SP1 2.6.5-3.18.1
  • rmt-server SLES for SAP 15, SLES 15-LTSS, SLE High Performance Computing 15-LTSS +1 more 2.6.5-3.34.1
  • rmt-server SLE Module for Server Applications 15 SP2, SLE Module for Public Cloud 15 SP2 2.6.5-3.3.1
  • rubygem-activesupport-4_2 OpenStack Cloud Crowbar 9, OpenStack Cloud Crowbar 8, OpenStack Cloud 7 4.2.9-7.9.1
  • rubygem-activesupport-5_1 SLE High Availability Extension 15 SP2, SLE High Availability Extension 15 SP1, SLE High Availability Extension 15 5.1.4-3.3.1

suse advisories SUSE-SU-2020:3160-1SUSE-SU-2020:3147-1SUSE-SU-2020:3036-1SUSE-SU-2020:2929-1SUSE-SU-2020:2899-1

  • rmt-server openSUSE Tumbleweed 2.6.13-1.1
  • rubygem-activesupport-6.0 openSUSE Tumbleweed 6.0.4.4-1.1
  • rmt-server openSUSE Leap 15.1 2.6.5-lp151.2.18.2
  • rmt-server openSUSE Leap 15.2 2.6.5-lp152.2.3.1
  • rubygem-activesupport-5_1 openSUSE Leap 15.2 5.1.4-lp152.4.3.1
  • rubygem-activesupport-5_1 openSUSE Leap 15.1 5.1.4-lp151.3.3.1

opensuse advisories openSUSE-SU-2024:10589-1openSUSE-SU-2024:11828-1openSUSE-SU-2020:2000-1openSUSE-SU-2020:1993-1openSUSE-SU-2020:1679-1openSUSE-SU-2020:1677-1

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2020-8165 updated cvss 0.0

rubygem-activesupport: potentially unintended unmarshalling of user-provided objects in MemCacheStore and RedisCacheStore

  • Red Hat CloudForms Management Engine 5 cfme-gemset
    affected: workaround, no fix planned “Red Hat has investigated whether a possible mitigation exists for this issue, and has not been able to identify a practical example. Please update as soon as possible.”
  • Red Hat 3scale API Management Platform 2 system Red Hat OpenShift Container Platform 3.11 rubygem-activesupport Red Hat Storage 3 rubygem-activesupport
    affected: workaround, no fix available “Red Hat has investigated whether a possible mitigation exists for this issue, and has not been able to identify a practical example. Please update as soon as possible.”
  • Red Hat Satellite 6.9 tfm 6.1-4.el7sat, kobo 0.5.1-1.el7sat, pulp 2.21.5-2.el7sat, gofer 2.12.5-7.el7sat, libsolv 0.7.12-2.el7pc, receptor 0.6.3-1.el7ar, +639 more Red Hat Satellite Capsule 6.9 tfm 6.1-4.el7sat, kobo 0.5.1-1.el7sat, pulp 2.21.5-2.el7sat, gofer 2.12.5-7.el7sat, libsolv 0.7.12-2.el7pc, future 0.16.0-11.el7sat, +238 more
    fixed: vendor fix “Red Hat has investigated whether a possible mitigation exists for this issue, and has not been able to identify a practical example. Please update as soon as possible.” RHSA-2021:1313
  • Red Hat CloudForms Management Engine 5 cfme-amazon-smartstate Red Hat OpenShift Container Platform 4 openshift4/ose-logging-fluentd
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

45.73% chance of exploitation in the next 30 days, higher than 98% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • hackerone.com https://hackerone.com/reports/413388 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
NVD 3.1 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD 2.0 7.5 AV:N/AC:L/Au:N/C:P/I:P/A:P
GitHub 3.1 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected packages

ecosystem package affected fixed in
rubygems activesupport
>=5.0.0, <5.2.4.3
>=6.0.0, <6.0.3.1
5.2.4.3
6.0.3.1

Affected products

  • n/a https://github.com/rails/rails

Classification

Weakness
  • CWE-502 Deserialization of Untrusted Data
Technology feeds

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.