CVE-2022-31163 is a high-severity (CVSS 7.5) Path Traversal vulnerability in tzinfo. 1 public exploit or proof-of-concept reference is indexed, so weaponization risk is real. A fix is available for tzinfo — see the affected versions and patch details below.
TZInfo relative path traversal vulnerability allows loading of arbitrary files
Exploitation Status
Proof-of-concept exploit code exists
- CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
- A successful exploit gives an attacker total control of the affected component, not partial access.
Exploitation and automatability from CISA’s SSVC triage for CVE-2022-31163.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
Where this sits among everything scored
Real-World Exposure
tzinfo💎tzinfoReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects RubyGems packages — download data is not available via public APIs for these ecosystems.
Description
Impact
Affected versions
- 0.3.60 and earlier.
- 1.0.0 to 1.2.9 when used with the Ruby data source (tzinfo-data).
Vulnerability
With the Ruby data source (the tzinfo-data gem for tzinfo version 1.0.0 and later and built-in to earlier versions), time zones are defined in Ruby files. There is one file per time zone. Time zone files are loaded with require on demand. In the affected versions, TZInfo::Timezone.get fails to validate time zone identifiers correctly, allowing a new line character within the identifier. With Ruby version 1.9.3 and later, TZInfo::Timezone.get can be made to load unintended files with require, executing them within the Ruby process.
For example, with version 1.2.9, you can run the following to load a file with path /tmp/payload.rb:
TZInfo::Timezone.get("foo\n/../../../../../../../../../../../../../../../../tmp/payload")
The exact number of parent directory traversals needed will vary depending on the location of the tzinfo-data gem.
TZInfo versions 1.2.6 to 1.2.9 can be made to load files from outside of the Ruby load path. Versions up to and including 1.2.5 can only be made to load files from directories within the load path.
This could be exploited in, for example, a Ruby on Rails application using tzinfo version 1.2.9, that allows file uploads and has a time zone selector that accepts arbitrary time zone identifiers. The CVSS score and severity have been set on this basis.
Versions 2.0.0 and later are not vulnerable.
Patches
Versions 0.3.61 and 1.2.10 include fixes to correctly validate time zone identifiers (commit 9eddbb5c0e682736f61d0dd803b6031a5db9eadf for 0.3.x and commit 9905ca93abf7bf3e387bd592406e403cd18334c7 for 1.2.x).
Note that version 0.3.61 can still load arbitrary files from the Ruby load path if their name follows the rules for a valid time zone identifier and the file has a prefix of tzinfo/definition within a directory in the load path. For example if /tmp/upload was in the load path, then TZInfo::Timezone.get('foo') could load a file with path /tmp/upload/tzinfo/definition/foo.rb. Applications should ensure that untrusted files are not placed in a directory on the load path.
Workarounds
As a workaround, the time zone identifier can be validated before passing to TZInfo::Timezone.get by ensuring it matches the regular expression \A[A-Za-z0-9+\-_]+(?:\/[A-Za-z0-9+\-_]+)*\z.
For more information
If you have any questions or comments about this advisory:
- Open an issue in the tzinfo repository.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 💎RubyGems | tzinfo | all versions | 0.3.61bundle update tzinfo --conservative |
| 💎RubyGems | tzinfo | ≥ 1.0.0&&< 1.2.10 | 1.2.10bundle update tzinfo --conservative |
Affected Products
debian linuxdebiantzinfotzinfo_projectResearch 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 tzinfo, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update tzinfo to 0.3.61 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2022-31163 is resolved across your whole dependency graph.
Workarounds
Resolve every user-supplied path to its canonical form and reject anything that escapes the intended directory, and run the component under an account that has no read or write access outside the directory it legitimately serves.
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.
As a workaround, the time zone identifier can be validated before passing to TZInfo::Timezone.get by ensuring it matches the regular expression \A[A-Za-z0-9+\-_]+(?:\/[A-Za-z0-9+\-_]+)*\z.Source: Red Hat security advisory for CVE-2022-31163 (CC BY 4.0)
| Product | Fixed in | Advisory |
|---|---|---|
| Red Hat Gluster Storage 3.5 for RHEL 7 | rubygem-tzinfo-0:1.2.10-1.el7rhgs | RHSA-2023:1486 |
| Red Hat Satellite 6.11 for RHEL 7 | tfm-rubygem-tzinfo-0:1.2.10-1.el7sat | RHSA-2022:7242 |
| Red Hat Satellite 6.13 for RHEL 8 | rubygem-tzinfo-0:2.0.5-1.el8sat | RHSA-2023:2097 |
Frequently Asked Questions
Is CVE-2022-31163 in your dependencies?
Find it across RubyGems, including transitive dependencies.