CVE-2020-1733 is a medium-severity (CVSS 5) CWE-377 vulnerability in ansible. 1 public exploit reference exists, so weaponization risk is real. A fix is available for ansible — see the affected versions and patch details below.
Ansible vulnerable to Exposure of Resource to Wrong Sphere and Insecure Temporary File
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
CVE-2020-1733 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.
Where this sits among everything scored
Of 385,386 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.
Real-World Exposure
ansible🐍ansible🐍ansibleReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.
Description
A race condition flaw was found in Ansible Engine 2.7.17 and prior, 2.8.9 and prior, 2.9.6 and prior when running a playbook with an unprivileged become user. When Ansible needs to run a module with become user, the temporary directory is created in /var/tmp. This directory is created with "umask 77 && mkdir -p <dir>"; this operation does not fail if the directory already exists and is owned by another user. An attacker could take advantage to gain control of the become user as the target directory can be retrieved by iterating '/proc/<pid>/cmdline'.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | ansible | all versions | 2.7.17pip install --upgrade 'ansible==2.7.17' |
| 🐍PyPI | ansible | ≥ 2.8.0a1&&< 2.8.11 | 2.8.11pip install --upgrade 'ansible==2.8.11' |
| 🐍PyPI | ansible | ≥ 2.9.0a1&&< 2.9.7 | 2.9.7pip install --upgrade 'ansible==2.9.7' |
Affected Products
debian linuxdebianfedorafedoraprojectansibleredhatansible towerredhatcloudforms management engineredhatopenstackredhatResearch use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for ansible, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update ansible to 2.7.17 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2020-1733 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
Fixing This On Your OS
If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.
Ansible Engine 2.7.16, 2.8.10, and 2.9.6 as well as previous versions are affected. Ansible Tower 3.4.5, 3.5.5 and 3.6.3 as well as previous versions are affected. In Red Hat OpenStack Platform, because the flaw has a lower impact, ansible is not directly customer exposed, and the fix would require a substantial…
This issue can be mitigated by mounting the proc filesystem with hidepid=2 option (https://www.kernel.org/doc/Documentation/filesystems/proc.txt). This way only the user used by Ansible will be able to perform the attack as users on the system will be able to access only their processes /proc/$PID/ directories. Also note that mounting proc filesystem with hidepid=2 might require re-mounting it on unpatched kernels, due to a kernel bug (see https://unix.stackexchange.com/questions/584054/why-procfs-mount-option-only-working-on-remount), there will be hidepid=3 in the future (https://patchwork.kernel.org/patch/11310217/).Source: Red Hat security advisory for CVE-2020-1733 (CC BY 4.0)
| Product | Fixed in | Advisory |
|---|---|---|
| Red Hat Ansible Engine 2.7 for RHEL 7 | ansible-0:2.7.17-1.el7ae | RHSA-2020:1544 |
| Red Hat Ansible Engine 2.8 for RHEL 7 | ansible-0:2.8.11-1.el7ae | RHSA-2020:1543 |
| Red Hat Ansible Engine 2.9 for RHEL 7 | ansible-0:2.9.7-1.el7ae | RHSA-2020:1541 |
| Red Hat Ansible Engine 2 for RHEL 7 | ansible-0:2.9.7-1.el7ae | RHSA-2020:1542 |
Frequently Asked Questions
Is CVE-2020-1733 in your dependencies?
Find it across PyPI, including transitive dependencies.