Buffer overflow in DNS resolver functions that perform lookup of network names and addresses, as used in BIND 4.9.8 and ported to glibc 2.2.5 and earlier, allows remote malicious DNS servers to execute arbitrary code through a subroutine used by functions such as getnetbyname and getnetbyaddr.

The remote BIND server, according to its version number, is vulnerable to a remote buffer overflow within its resolver code. An attacker may be able to execute arbitrary code by having the remote DNS server make a request and send back a malicious DNS response with an invalid length field.

The remote BIND 9 server is vulnerable to a buffer overflow which may be exploited by an attacker to gain a shell on this host, or disable this service entirely.

A buffer overflow vulnerability was found in the way that the glibc resolver handles the resolution of network names and addresses via DNS in glibc versions 2.2.5 and earlier. Only systems using the 'dns' entry in the 'networks' database in /etc/nsswitch.conf are vulnerable to this issue. By default, Mandrake Linux has this database set to 'files' and is not vulnerable. Likewise, a similar bug is in the glibc-compat packages which provide compatability for programs compiled against 2.0.x versions of glibc.

Updated glibc packages are available which fix a buffer overflow in the XDR decoder and two vulnerabilities in the resolver functions.

[updated 8 aug 2002] Updated packages have been made available, as the original errata introduced a bug which could cause calloc() to crash on 32-bit platforms when passed a size of 0. These updated errata packages contain a patch to correct this bug.

The glibc package contains standard libraries which are used by multiple programs on the system. Sun RPC is a remote procedure call framework which allows clients to invoke procedures in a server process over a network. XDR is a mechanism for encoding data structures for use with RPC. NFS, NIS, and other network services that are built upon Sun RPC. The glibc package contains an XDR encoder/decoder derived from Sun's RPC implementation which was recently demonstrated to be vulnerable to a heap overflow.

An error in the calculation of memory needed for unpacking arrays in the XDR decoder can result in a heap buffer overflow in glibc 2.2.5 and earlier. Depending upon the application, this vulnerability may be exploitable and could lead to arbitrary code execution.
(CVE-2002-0391)

A buffer overflow vulnerability has been found in the way the glibc resolver handles the resolution of network names and addresses via DNS (as per Internet RFC 1011). Version 2.2.5 of glibc and earlier versions are affected. A system would be vulnerable to this issue if the 'networks' database in the /etc/nsswitch.conf file includes the 'dns' entry. By default, Red Hat Linux Advanced Server ships with 'networks' set to 'files' and is therefore not vulnerable to this issue. (CVE-2002-0684)

A related issue is a bug in the glibc-compat packages, which provide compatibility for applications compiled against glibc version 2.0.x.
Applications compiled against this version (such as those distributed with early Red Hat Linux releases 5.0, 5.1, and 5.2) could also be vulnerable to this issue. (CVE-2002-0651)

All users should upgrade to these errata packages which contain patches to the glibc libraries and therefore are not vulnerable to these issues.

Thanks to Solar Designer for providing patches for this issue.

The remote BIND server, according to its version number, is vulnerable to a remote buffer overflow within its resolver code.

An attacker may be able to execute arbitrary code by having the remote DNS server make a request and send back a malicious DNS response with an invalid length field.

The remote BIND 9 DNS server, according to its version number, is vulnerable to a buffer overflow which may allow an attacker to gain a shell on this host or to disable this server.

ID	Name	Product	Family	Severity
1008	ISC BIND < 4.9.5 Multiple DNS Resolver Functions Remote Overflow (deprecated)	Nessus Network Monitor	DNS Servers	critical
1002	ISC BIND 9 Multiple DNS Resolver Functions Remote Overflow	Nessus Network Monitor	DNS Servers	critical
13953	Mandrake Linux Security Advisory : glibc (MDKSA-2002:050)	Nessus	Mandriva Local Security Checks	high
12318	RHEL 2.1 : glibc (RHSA-2002:167)	Nessus	Red Hat Local Security Checks	critical
11510	ISC BIND < 4.9.5 DNS Resolver Functions Remote Overflow	Nessus	DNS	critical
11318	ISC BIND < 9.2.2 DNS Resolver Functions Remote Overflow	Nessus	DNS	critical

Detections

Analytics

CVE-2002-0684

critical

Tenable Plugins

critical

critical

high

critical

critical

critical