CVE-2022-31159 is a high-severity (CVSS 7.9) Path Traversal vulnerability in com.amazonaws:aws-java-sdk-s3. 1 public exploit reference exists, so weaponization risk is real. A fix is available for com.amazonaws:aws-java-sdk-s3 — see the affected versions and patch details below.
Partial Path Traversal in com.amazonaws:aws-java-sdk-s3
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-2022-31159.
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-2022-31159 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 378,567 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
com.amazonaws:aws-java-sdk-s3Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Maven packages — download data is not available via public APIs for these ecosystems.
Description
Overview
A partial-path traversal issue exists within the downloadDirectory method in the AWS S3 TransferManager component of the AWS SDK for Java v1. Applications using the SDK control the destinationDirectory argument, but S3 object keys are determined by the application that uploaded the objects. The downloadDirectory method allows the caller to pass a filesystem object in the object key but contained an issue in the validation logic for the key name. A knowledgeable actor could bypass the validation logic by including a UNIX double-dot in the bucket key. Under certain conditions, this could permit them to retrieve a directory from their S3 bucket that is one level up in the filesystem from their working directory.
This issue’s scope is limited to directories whose name prefix matches the destinationDirectory. E.g. for destination directory/tmp/foo, the actor can cause a download to /tmp/foo-bar, but not /tmp/bar.
Versions of the AWS Java SDK for S3 v1 before and including v1.12.260 are affected by this issue.
Impact
If com.amazonaws.services.s3.transfer.TransferManager::downloadDirectory is used to download an untrusted buckets contents, the contents of that bucket can be written outside of the intended destination directory.
Root Cause
The com.amazonaws.services.s3.transfer.TransferManager::downloadDirectory contains a partial-path traversal vulnerability.
This is due to the guard logic in leavesRoot containing an insufficient protection against partial-path traversal.
The application controls the localBaseDirectory argument, but the key comes from the AWS bucket entry (ie. can be attacker controlled). The above bit of logic can be bypassed with the following payloads:
// The following will return 'false', although the attacker value will "leave" the `/usr/foo` directory
leavesRoot(new File("/usr/foo"), "/../foo-bar/bar")
This guard is used here which should guard against path traversal, however leavesRoot is an insufficient guard:
True Root cause
If the result of parent.getCanonicalPath() is not slash terminated it allows for partial path traversal.
Consider
"/usr/outnot".startsWith("/usr/out"). The check is bypassed althoughoutnotis not under theoutdirectory. The terminating slash may be removed in various places. On Linuxprintln(new File("/var/"))returns/var, butprintln(new File("/var", "/"))-/var/, howeverprintln(new File("/var", "/").getCanonicalPath())-/var. - @JarLob (Jaroslav Lobačevski)
Patches
Upgrade to the AWS SDK for Java >= 1.12.261, if you are on a version < 1.12.261.
Workarounds
When calling com.amazonaws.services.s3.transfer.TransferManager::downloadDirectory pass a KeyFilter that forbids S3ObjectSummary objects that getKey method return a string containing the substring .. .
References
Similar vulnerabilities:
- ESAPI (The OWASP Enterprise Security API) - https://nvd.nist.gov/vuln/detail/CVE-2022-23457
For more information
If you have any questions or comments about this advisory, please contact AWS's Security team.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| ☕Maven | com.amazonaws:aws-java-sdk-s3 | all versions | 1.12.261com.amazonaws:aws-java-sdk-s3:1.12.261 |
Research 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 com.amazonaws:aws-java-sdk-s3, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update com.amazonaws:aws-java-sdk-s3 to 1.12.261 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2022-31159 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-2022-31159 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2022-31159. 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-2022-31159 in your dependencies?
O3 Security finds CVE-2022-31159 across Maven dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.