Description
lsh daemon (lshd) does not properly return from certain functions in (1) read_line.c, (2) channel_commands.c, or (3) client_keyexchange.c when long input is provided, which could allow remote attackers to execute arbitrary code via a heap-based buffer overflow attack.
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 12 | lsh-utils | 1.4.2-6 | — |
| Debian 3.0 | lsh-utils | 1.2.5-2woody3 | DSA-717-1 |
Public exploits
Exploit or proof-of-concept code for this vulnerability is publicly available, which lowers the bar for attackers. Treat it as a reason to patch sooner.
Third-party code, not reviewed by us. Public PoCs are sometimes fake or contain malware. Read the code first and run it only in an isolated lab, against systems you are authorised to test.
Exploit-DB 2
- LSH 1.x - Remote Buffer Overflow (1) EDB-23161 · remote · Sep 19, 2003 · verified
- LSH 1.x - Remote Buffer Overflow (2) EDB-23162 · remote · Sep 19, 2003 · verified
Sources: PoC-in-GitHub, Metasploit Framework, Exploit-DB — updated daily. Only links are listed; no exploit code is hosted here.
Advisories 1
- DSA-717-1 lsh-utils - buffer overflow, typo Debian Security (DSA / DLA) · Mar 9, 2026
References
- 20030919 lsh patch (was Re: [Full-Disclosure] new ssh exploit?) mailing-list
- http://lists.lysator.liu.se/pipermail/lsh-bugs/2003q3/000120.html
- http://bugs.debian.org/211662
- DSA-717 vendor-advisory
- 20030920 LSH: Buffer overrun and remote root compromise in lshd mailing-list
- 20030919 Remote root vuln in lsh 1.4.x mailing-list