Published:
10 April 2000
Protect yourself against future threats.
-----BEGIN PGP SIGNED MESSAGE----- =========================================================================== AUSCERT External Security Bulletin Redistribution ESB-2000.065 -- FreeBSD-SA-00:11 ircII port contains a remote overflow 11 April 2000 =========================================================================== The FreeBSD Security Team has released the following advisory concerning a vulnerability in ircii's dcc chat capability. This vulnerability may allow a remote user to execute code as the user of the ircii client. This is the same vulnerability as previously described in AUSCERT External Security Bulletin ESB-2000.060. - --------------------------BEGIN INCLUDED TEXT-------------------- - -----BEGIN PGP SIGNED MESSAGE----- ============================================================================= FreeBSD-SA-00:11 Security Advisory FreeBSD, Inc. Topic: ircII port contains a remote overflow Category: ports Module: ircII Announced: 2000-04-10 Credits: Derek Callaway <super@UDEL.EDU> via BugTraq "bladi" <bladi@EUSKALNET.NET> via BugTraq Affects: Ports collection before the correction date. Corrected: 2000-03-19 FreeBSD only: NO I. Background ircII is a popular text-mode IRC client. II. Problem Description ircII version 4.4 contained a remotely-exploitable buffer overflow in the /DCC CHAT command which allows remote users to execute arbitrary code as the client user. The bug was originally reported in 1997 in a much older version of ircII, but was apparently not corrected at the time, and the problem was recently rediscovered independently. Development on the version of ircII previously in ports ceased several years ago, and has been taken up by a new group who have fixed this problem (and possibly others). FreeBSD now provides this new version of ircII. The ircII port is not installed by default, nor is it "part of FreeBSD" as such: it is part of the FreeBSD ports collection, which contains over 3200 third-party applications in a ready-to-install format. FreeBSD 4.0 did not ship with the ircII package available because this vulnerability was reported to us late in the release cycle and it was not possible to upgrade the port in time. FreeBSD makes no claim about the security of these third-party applications, although an effort is underway to provide a security audit of the most security-critical ports. III. Impact A remote user can cause arbitrary code to be executed on the local system as the user running ircII. If you have not chosen to install the ircII port/package, then your system is not known to be vulnerable to this problem, although there are several other IRC clients which are derived from ircII including Epic and BitchX. At this time it is unknown whether other clients are vulnerable to this problem. IV. Workaround Remove the ircII port, if you you have installed it. V. Solution 1) Upgrade your entire ports collection and rebuild the ircII port. 2) Reinstall a new package dated after the correction date, obtained from: ftp://ftp.FreeBSD.org/pub/FreeBSD/ports/i386/packages-3-stable/irc/ircII-4.4S.tgz ftp://ftp.FreeBSD.org/pub/FreeBSD/ports/i386/packages-3-stable/irc/ircII-4.4S.tgz ftp://ftp.FreeBSD.org/pub/FreeBSD/ports/alpha/packages-3-stable/irc/ircII-4.4S.tgz ftp://ftp.FreeBSD.org/pub/FreeBSD/ports/i386/packages-5-current/irc/ircII-4.4S.tgz ftp://ftp.FreeBSD.org/pub/FreeBSD/ports/alpha/packages-5-current/irc/ircII-4.4S.tgz 3) download a new port skeleton for the ircII port from: http://www.freebsd.org/ports/ and use it to rebuild the port. 4) Use the portcheckout utility to automate option (3) above. The portcheckout port is available in /usr/ports/devel/portcheckout or the package can be obtained from: ftp://ftp.freebsd.org/pub/FreeBSD/ports/packages/devel/portcheckout-1.0.tgz - -----BEGIN PGP SIGNATURE----- Version: 2.6.2 iQCVAwUBOPJAMVUuHi5z0oilAQHKpgQAjdphg+Xaw4J7J5+dowvgrgoggA4YG0P5 a7Nodawpvm2ya8jBStmi0cs3LhYIXZUPQfY3lqiAfEbf4Ndd4r5KUbQ+iAjgz4lZ XHG0PjUGE98dK3eHZbLszaMIwPbBaCyicCD0gLPCVm40O0VOlqY+WHO9MfITgpec GFF3l8b8Ym0= =IU1d - -----END PGP SIGNATURE----- - --------------------------END INCLUDED TEXT-------------------- This security bulletin is provided as a service to AusCERT's members. As AusCERT did not write the document quoted above, AusCERT has had no control over its content. The decision to use any or all of this information is the responsibility of each user or organisation, and should be done so in accordance with site policies and procedures. NOTE: This is only the original release of the security bulletin. It may not be updated when updates to the original are made. If downloading at a later date, it is recommended that the bulletin is retrieved directly from the original authors to ensure that the information is still current. Contact information for the authors of the original document is included in the Security Bulletin above. If you have any questions or need further information, please contact them directly. Previous advisories and external security bulletins can be retrieved from: http://www.auscert.org.au/Information/advisories.html If you believe that your system has been compromised, contact AusCERT or your representative in FIRST (Forum of Incident Response and Security Teams). Internet Email: auscert@auscert.org.au Facsimile: (07) 3365 7031 Telephone: (07) 3365 4417 (International: +61 7 3365 4417) AusCERT personnel answer during Queensland business hours which are GMT+10:00 (AEST). On call after hours for emergencies. -----BEGIN PGP SIGNATURE----- Version: 2.6.3i Charset: noconv Comment: ftp://ftp.auscert.org.au/pub/auscert/AUSCERT_PGP.key iQCVAwUBOXXR2Ch9+71yA2DNAQFi2QQAiJwNpQblHCRvsxUs1E2xvkOkphkjsE6x w+9D+ek+toUk2UssJcW7jsVP8x0iHd3tbViIUnonS/eeAnl1fAb75qA89oX67O7p AiIanJyLKRN40HmhKvVcoq2V4NEh888mgOraUwRvmGk45JGi6QKqDotJQZwqqcB2 3ZmR53ihE+A= =yzua -----END PGP SIGNATURE-----