FTP: WU-FTPD and BSDi-ftpd SITE EXEC Race Condition

This signature detects attempts to exploit a known vulnerability against the PASS command in Wu-ftpd 2.6.0 and BSDi-ftpd. Attackers can send a maliciously crafted PASS request to an FTP server to execute arbitrary commands as root.

Extended Description

Washington University ftp daemon (wu-ftpd) is a very popular unix ftp server shipped with many distributions of Linux and other UNIX operating systems. Wu-ftpd is vulnerable to a very serious remote attack in the SITE EXEC implementation. Because of user input going directly into a format string for a *printf function, it is possible to overwrite important data, such as a return address, on the stack. When this is accomplished, the function can jump into shellcode pointed to by the overwritten eip and execute arbitrary commands as root. While exploited in a manner similar to a buffer overflow, it is actually an input validation problem. Anonymous ftp is exploitable making it even more serious as attacks can come anonymously from anywhere on the internet. It should be noted that the SITE INDEX command is affected as well.

Affected Products

Hp hp-ux

References

BugTraq: 1387

CVE: CVE-1999-0955

URL: http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2000-0573

Short Name

FTP:OVERFLOW:WUBSD-SE-RACE

Severity

Critical

Recommended

False

Recommended Action

Drop

FTP: WU-FTPD and BSDi-ftpd SITE EXEC Race Condition

Extended Description

Affected Products

References

Found a potential security threat?