CVE-2022-23538 is a medium-severity (CVSS 5.2) CWE-522 vulnerability in github.com/sylabs/scs-library-client. A fix is available for github.com/sylabs/scs-library-client — see the affected versions and patch details below.
User credentials leaked to third-party service via HTTP redirect in scs-library-client
Exploitation Status
No confirmed exploitation observed yet
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2022-23538.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
CVE-2022-23538 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 377,636 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
github.com/sylabs/scs-library-client🐹github.com/sylabs/scs-library-clientReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.
Description
Impact
When the scs-library-client is used to pull a container image, with authentication, the HTTP Authorization header sent by the client to the library service may be incorrectly leaked to an S3 backing storage provider. This occurs in a specific flow, where the library service redirects the client to a backing S3 storage server, to perform a multi-part concurrent download.
Depending on site configuration, the S3 service may be provided by a third party. An attacker with access to the S3 service may be able to extract user credentials, allowing them to impersonate the user.
The vulnerable multi-part concurrent download flow, with redirect to S3, is only used when communicating with a Singularity Enterprise 1.x installation, or third party server implementing this flow.
Interaction with Singularity Enterprise 2.x, and Singularity Container Services (cloud.sylabs.io), does not trigger the vulnerable flow.
We encourage all users to update. Users who interact with a Singularity Enterprise 1.x installation, using a 3rd party S3 storage service, are advised to revoke and recreate their authentication tokens within Singularity Enterprise.
Patches
The security issue was identified after the integration of a bug-fix commit 68ac4ca into the previously released scs-library-client 1.3.4. This commit fixes the security issue in the 1.3 series.
scs-library-client 1.4.2 contains a fix for the same vulnerability in the 1.4 series, as commit eebd7ca.
Workarounds
There is no workaround available at this time.
As above, access to Singularity Enterprise 2.x, or Singularity Container Services (cloud.sylabs.io), does not trigger the vulnerable flow.
References
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/sylabs/scs-library-client | ≥ 1.4.0&&< 1.4.2 | 1.4.2go get github.com/sylabs/scs-library-client@v1.4.2 |
| 🐹Go | github.com/sylabs/scs-library-client | all versions | 1.3.4go get github.com/sylabs/scs-library-client@v1.3.4 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/sylabs/scs-library-client, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update github.com/sylabs/scs-library-client to 1.4.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2022-23538 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.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2022-23538 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2022-23538. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2022-23538 in your dependencies?
O3 Security finds CVE-2022-23538 across Go dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.