Copyright 2024 - CSIM - Asian Institute of Technology

[Date Prev] [Date Next] [Thread Prev] [Thread Next] [Date Index] [Thread Index]

Subject: UPDATE - CERT Advisory CA-2002-19 Buffer Overflows in Multiple DNS Resolver Libraries
From: CERT Advisory <This email address is being protected from spambots. You need JavaScript enabled to view it.>
Date: Tue, 27 Aug 2002 21:58:00 -0400


-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1


UPDATE:  CERT Advisory CA-2002-19 Buffer Overflows in Multiple DNS
Resolver Libraries


August 27, 2002


An important change has been made to CERT Advisory CA-2002-19.


The workaround of using a local caching DNS server is not completely
effective.  Specifically, some malicious DNS responses can be cached,
reconstructed, and passed on to systems that may have vulnerable DNS
resolver libraries.

For the most current information, including which systems are affected
and vendor statements, please see the documents listed at the end of
this message.


The following change was made to section III. of CA-2002-19:

======================================================================

III. Solution

Upgrade to a corrected version of the DNS resolver libraries

    [no change]

Use of a local caching DNS server is not an effective workaround

    When this advisory was initially published, it was thought that a
    caching DNS server that reconstructs DNS responses would prevent
    malicious code from reaching systems with vulnerable resolver
    libraries.

    This workaround is not sufficient. It does not prevent some DNS
    responses that contain malicious code from reaching clients,
    whether or not the responses are reconstructed by a local caching
    DNS server. DNS responses containing code that is capable of
    exploiting the vulnerabilities described in VU#803539 and
    VU#542971 can be cached and reconstructed before being transmitted
    to clients. Since the server may cache the responses, the
    malicious code could persist until the server's cache is purged or
    the entries expire.

    The only complete solution to this problem is to upgrade to a
    corrected version of the DNS resolver libraries as noted above.

======================================================================


The following documents have been revised:

    CERT Advisory CA-2002-19
    http://www.cert.org/advisories/CA-2002-19.html

    Vulnerability Note VU#803539
    http://www.kb.cert.org/vuls/id/803539

    Vulnerability Note VU#542971
    http://www.kb.cert.org/vuls/id/542971



-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.0.6 (GNU/Linux)
Comment: For info see http://www.gnupg.org

iQCVAwUBPWwncKCVPMXQI2HJAQKyqwP+NByjCM2eHhboD9L5PIrDTVs6eXv0qFcG
zc8Hv1j/7I9I7oK4JwJUKLO83DvLxsEyCd+ooV32eBSw4UFsh+vbZz9On9XkDApf
f6VRPIyKNBAQp8p1x+LpuH5Q1qIVMXBo1Y6NtiwAcn/WnTDq8McGSqCrMV+NRChI
EfhhbZqnW6s=
=yEmz
-----END PGP SIGNATURE-----


Powered by: MHonArc

Login Form

Search

School of Engineering and technologies     Asian Institute of Technology