GHSA-c28r-hw5m-5gv3
HIGHPartial Path Traversal in com.amazonaws:aws-java-sdk-s3
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.
Blast Radius
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 | 1.12.261 |
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. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
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 GHSA-c28r-hw5m-5gv3 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 pinpoints whether GHSA-c28r-hw5m-5gv3 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to GHSA-c28r-hw5m-5gv3. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-c28r-hw5m-5gv3 in your dependencies?
O3 detects GHSA-c28r-hw5m-5gv3 across Maven dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.