CVE-2021-43795
Path Traversal in com.linecorp.armeria:armeria
Impact
### Impact An attacker can access an Armeria server's local file system beyond its restricted directory by sending an HTTP request whose path contains `%2F` (encoded `/`), such as `/files/..%2Fsecrets.txt`, bypassing Armeria's path validation logic. ### Patches Armeria 1.13.4 or above contains the hardened path validation logic that handles `%2F` properly. ### Workarounds This vulnerability can be worked around by inserting a decorator that performs an additional validation on the request path, e.g. ```java Server .builder() .serviceUnder( "/files", FileService .of(...) .decorate((delegate, ctx, req) -> { String path = req.headers().path(); if (path.contains("%2f") || path.contains("%2F")) { return HttpResponse.of(HttpStatus.BAD_REQUEST); } return delegate.serve(ctx, req); }) ) .build() ``` ### For more information If you have any questions or comments about this advisory: * Open an issue in [line/armeria](https://github.com/line/armeria) * Chat with us at [Slack](https://armeria.dev/s/slack) ### Credits This vulnerability was originally reported by Abdallah Zaher ([elcayser-0x0a](https://hackerone.com/elcayser-0x0a?type=user)).
Affected packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| maven | com.linecorp.armeria:armeria | >= 1.12.0, < 1.13.4 | 1.13.4 |
Affected products
| Vendor | Product | Affected versions |
|---|---|---|
| Linecorp | Armeria | before 1.13.4 |
Weakness classification
References
- NVD record
- CVE.org record
- GitHub advisory
- https://github.com/line/armeria/commit/e2697a575e9df6692b423e02d731f293c1313284
- https://github.com/line/armeria/pull/3855
- https://github.com/line/armeria/security/advisories/GHSA-8fp4-rp6c-5gcv
- https://github.com/advisories/GHSA-8fp4-rp6c-5gcv
- https://nvd.nist.gov/vuln/detail/CVE-2021-43795