DNS: BIND NXT Overflow

This protocol anomaly is a suspiciously large NXT resource record in a DNS transaction. BIND versions 8.2 through 8.2.1 are vulnerable to a buffer overflow in the processing of NXT resource records.

Extended Description

There are several vulnerabilities in recent BIND packages (pre 8.2.2). The first is a buffer overflow condition which is a result of BIND improperly validating NXT records. The consequence of this being exploited is a remote root compromise (assuming that BIND is running as root, which is default). The second is a denial of service which can occur if BIND does not validate SIG records properly. The next is a bug which allows attackers to cause BIND to consume more file descriptors than can be managed, causing named to crash. The fourth vulnerability is another denial of service which can be caused locally if certain permission conditions are met when validating zone information loaded from disk files. The last is a vulnerability which has to do with closing TCP sockets. If protocols for doing so are not adhered to, BIND can be paused for 120 seconds at a time.

Affected Products

Sgi irix

References

BugTraq: 0788

CVE: CVE-1999-0833

URL: http://www.securityfocus.com/bid/0788

Short Name

DNS:OVERFLOW:NXT-OVERFLOW

Severity

Critical

Recommended

False

Recommended Action

Drop Packet

DNS: BIND NXT Overflow

Extended Description

Affected Products

References

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