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Fencer Vulns
medium 6.7

CVE-2021-20253 json

A flaw was found in ansible-tower.

published 2021-03-09 5 y ago modified 2026-06-17 4 mo ago also EUVD-2021-7691

cvss
6.7
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.4%
EPSS 0.4% chance of exploitation in 30 days, percentile 35%
public exploits
0
none known

Summary

A flaw was found in ansible-tower. The default installation is vulnerable to Job Isolation escape allowing an attacker to elevate the privilege from a low privileged user to the awx user from outside the isolated environment. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability.

Patch / fix

  • redhat ansible_tower 3.6.7, 3.7.5, 3.8.2

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-2021-20253 updated cvss 6.7

ansible-tower: Privilege escalation via job isolation escape

  • Red Hat Ansible Automation Platform 1.2 ansible-tower
    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 Ansible Tower 3.6 for RHEL 7 ansible-tower-36/ansible-tower 3.6.7-1
    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-2021:0778
  • Red Hat Ansible Tower 3.7 for RHEL 7 ansible-tower-37/ansible-tower-rhel7 3.7.5-1
    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-2021:0779
  • Red Hat Ansible Tower 3.8 for RHEL 7 ansible-tower-38/ansible-tower-rhel7 3.8.2-1, ansible-tower-38/ansible-runner-rhel7 1.4.7-1
    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-2021:0780

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

0.41% chance of exploitation in the next 30 days, higher than 35% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
NVD 3.1 6.7 CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:U/C:H/I:H/A:H
NVD 2.0 3.5 AV:L/AC:H/Au:S/C:P/I:P/A:P

Affected products

  • n/a ansible-tower

Classification

Weakness
  • CWE-552 Files or Directories Accessible to External Parties

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.