Description
Kopia is a cross-platform backup tool for Windows, macOS, and Linux with fast incremental backups, client-side end-to-end encryption, compression, and data deduplication. Prior to 0.23.0, Kopia's HTTP server started with --without-password accepts unauthenticated requests to /api/v1/repo/exists and forwards attacker-supplied SFTP storage configuration to blob.NewStorage, where externalSSH: true and sshArguments containing -oProxyCommand=<cmd> can cause exec.CommandContext("ssh") to invoke the command through OpenSSH. This issue is fixed in version 0.23.0.
References4
Metrics
- CVSS 3.1
-
9.8
CRITICAL
Score source: CNA
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - EPSS — exploit probability
- 2% percentile: 76 · as of 15 November 2026
- CWE
- CWE-78CWE-306
Could this be exploited in your environment?
A patch closes the known hole. A penetration test shows what an attacker can still reach — with proof.