TELNET: FreeBSD telnetd Buffer Overflow Check

This signature detects attempts to exploit a known vulnerability against TELNET daemon. FreeBSD 4.3, NetBSD 1.5, and BSDI 4.1 are vulnerable. Attackers who can determine if a TELNET server is vulnerable, can create a denial-of-service condition or execute arbitrary code on the affected system.

Extended Description

A boundary condition error exists in telnet daemons derived from the BSD telnet daemon. Under certain circumstances, the buffer overflow can occur when a combination of telnet protocol options are received by the daemon. The function responsible for processing the options prepares a response within a fixed sized buffer, without performing any bounds checking. This vulnerability is now being actively exploited. A worm is known to be circulating around the Internet.

Affected Products

Cisco catalyst_5000,Openbsd openbsd

References

BugTraq: 3064

CVE: CVE-2001-0554

URL: http://www.kb.cert.org/vuls/id/745371

Short Name

TELNET:OVERFLOW:YBSD-OF-CHECK

Severity

Major

Recommended

False

Recommended Action

Drop

TELNET: FreeBSD telnetd Buffer Overflow Check

Extended Description

Affected Products

References

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