Description
C-Kermit 6.0.192 before 11.1.515 contains a buffer overflow vulnerability in tn_snenv() in ckctel.c that allows malicious Telnet servers to corrupt client memory via crafted NEW-ENVIRON SEND subnegotiation. Malicious or machine-in-the-middle servers can send oversized variable names before authentication, overflowing a 16-byte stack buffer and a miscomputed heap buffer to corrupt stack and heap memory.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| kermitproject | C-Kermit | 6.0.192 <11.1.515 | — |
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 | ckermit | 1:11.1.515-1 | — |
| Debian 13 | ckermit | No fix yet | — |
| Debian 12 | ckermit | No fix yet | — |
References
- https://github.com/OpenKermit/ckermit/security/advisories/GHSA-c5px-7h4c-gj8p
- https://github.com/OpenKermit/ckermit/commit/39ab009a365b97632e9975e1266fa618c4bdc59f
- https://github.com/OpenKermit/ckermit/commit/42cf6decb926f56d606a76262791aaf071955d25
- https://github.com/OpenKermit/ckermit/releases/tag/v11.1.515
- https://github.com/OpenKermit/ckermit/blob/v11.0.514/ckctel.c#L5622
- https://www.vulncheck.com/advisories/c-kermit-6.0.192-before-11.1.515-buffer-overflow-via-telnet-new-environ-negotiation