Description
A denial-of-service vulnerability exists in Sysax Multi-Server version 6.10 via its SSH daemon. A specially crafted SSH key exchange packet can trigger a crash in the service, resulting in loss of availability. The flaw is triggered during the handling of malformed key exchange data, including a non-standard byte (\x28) in place of the expected SSH protocol delimiter.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Sysax Software | Multi-Server | 6.10 | — |
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.
Metasploit 1 module
-
Sysax Multi-Server 6.10 SSHD Key Exchange Denial of Service
auxiliary/dos/windows/ssh/sysax_sshd_kexchange
Sources: PoC-in-GitHub, Metasploit Framework, Exploit-DB — updated daily. Only links are listed; no exploit code is hosted here.
References
- https://www.mattandreko.com/2013/04/08/sysax-multi-server-6.10-ssh-dos/ technical-description exploit
- https://raw.githubusercontent.com/rapid7/metasploit-framework/master/modules/auxiliary/dos/windows/ssh/sysax_sshd_kexchange.rb exploit
- https://www.sysax.com/ product
- https://www.vulncheck.com/advisories/sysax-multi-server-sshd-key-exchange-dos third-party-advisory