Description
sys_term.c in telnetd in FreeBSD 7.0-RELEASE and other 7.x versions deletes dangerous environment variables with a method that was valid only in older FreeBSD distributions, which might allow remote attackers to execute arbitrary code by passing a crafted environment variable from a telnet client, as demonstrated by an LD_PRELOAD value that references a malicious library.
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 1
- FreeBSD 7.0-RELEASE - Telnet Daemon Privilege Escalation EDB-8055 · local · Feb 16, 2009 · verified
Sources: PoC-in-GitHub, Metasploit Framework, Exploit-DB — updated daily. Only links are listed; no exploit code is hosted here.
References
- FreeBSD-SA-09:05 vendor-advisory
- freebsd-telnet-ldpreload-code-execution(48780) vdb-entry
- 33777 vdb-entry
- 20090214 FreeBSD zeroday mailing-list
- 8055 exploit