Description
A flaw has been found in janmojzis tinyssh up to 20250501. Impacted is an unknown function of the file tinyssh/crypto_sign_ed25519_tinyssh.c of the component Ed25519 Signature Handler. This manipulation causes improper verification of cryptographic signature. The attack is restricted to local execution. The attack's complexity is rated as high. The exploitability is considered difficult. The exploit has been published and may be used. Upgrading to version 20260301 is recommended to address this issue. Patch name: 9c87269607e0d7d20174df742accc49c042cff17. Upgrading the affected component is recommended.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| janmojzis | tinyssh | 20250501 | 20260301 |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | tinyssh | 20260301-1 | — |
| Debian 13 | tinyssh | No fix yet | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.10 | tinyssh | No fix yet | — |
| Ubuntu 26.04 LTS | tinyssh | No fix yet | — |
| Ubuntu 25.10 | tinyssh | No fix yet | — |
| Ubuntu 24.04 LTS | tinyssh | No fix yet | — |
| Ubuntu 22.04 LTS | tinyssh | No fix yet | — |
Show 2 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 20.04 LTS | tinyssh | No fix yet | — |
| Ubuntu 18.04 LTS | tinyssh | No fix yet | — |
References
- VDB-352358 | janmojzis tinyssh Ed25519 Signature crypto_sign_ed25519_tinyssh.c signature verification vdb-entry
- VDB-352358 | CTI Indicators (IOB, IOC, IOA) signature permissions-required
- Submit #774687 | GitHub tinyssh 20250501 Cryptographic Issues third-party-advisory
- https://github.com/janmojzis/tinyssh/issues/101 issue-tracking
- https://github.com/janmojzis/tinyssh/pull/102 issue-tracking patch
- https://github.com/janmojzis/tinyssh/issues/101#issue-3983586116 exploit issue-tracking
- https://github.com/janmojzis/tinyssh/commit/9c87269607e0d7d20174df742accc49c042cff17 patch
- https://github.com/janmojzis/tinyssh/releases/tag/20260301 patch
- https://github.com/janmojzis/tinyssh/ product