Description

CERT Polska has received a report about vulnerability in SzafirHost software and participated in coordination of its disclosure.

The vulnerability CVE-2026-13165: SzafirHost verifies the downloaded native library archive with one JarFile parser (reading the Central Directory) but extracts native libraries with JarInputStream parser (reading sequentially from local file headers). An attacker who controls the served archive can insert a malicious DLL/SO/DYLIB as a local-file-header entry between the last legitimate entry and the Central Directory, without adding it to the Central Directory. The signature verifier never sees the injected entry and accepts the archive as validly signed; the extractor reads it sequentially and writes the attacker library to the native temp directory with no hash check), while the archive-size check still passes. This can lead to remote code execution.

This issue was fixed in version 1.2.2.

Credits

We thank Mariusz Maik for the responsible vulnerability report.