Denial of Service attack on windows app using Netty
### Summary An unsafe reading of environment file could potentially cause a denial of service in Netty. When loaded on an Windows application, Netty attemps to load a file that does not exist. If an attacker creates such a large file, the Netty application crash. ### Details A similar issue was previously reported in https://github.com/netty/netty/security/advisories/GHSA-xq3w-v528-46rv This issue was fixed, but the fix was incomplete in that null-bytes were not counted against the input limit. ### PoC The PoC is the same as for https://github.com/netty/netty/security/advisories/GHSA-xq3w-v528-46rv with the detail that the file should only contain null-bytes; 0x00. When the null-bytes are encountered by the `InputStreamReader`, it will issue replacement characters in its charset decoding, which will fill up the line-buffer in the `BufferedReader.readLine()`, because the replacement character is not a line-break character. ### Impact Impact is the same as https://github.com/netty/netty/security/advisories/GHSA-xq3w-v528-46rv
describes (1)
Related CVEs.
| ID | severity | exploitable | ||
|---|---|---|---|---|
| CVE-2025-25193US | medium5.5 | — | ||
Netty, an asynchronous, event-driven network application framework, has a vulnerability in versions up to and including 4.1.118.Final. An unsafe reading of environment file could p… | ||||
references
External citations — patches, advisories, analysis.
- https://github.com/netty/nettyPACKAGE
- https://github.com/netty/netty/commit/d1fbda62d3a47835d3fb35db8bd42ecc205a5386WEB
- https://github.com/netty/netty/security/advisories/GHSA-389x-839f-4rhxWEB
- https://nvd.nist.gov/vuln/detail/CVE-2025-25193ADVISORY
- https://security.netapp.com/advisory/ntap-20250221-0006WEB
Advisories like this name the exposed products attackers go after on your perimeter. See what is exposed on your perimeter with a free passive scan.
Free scan