Specifications

SAFER – Vol. 3, Issue 6 38 © 2000 The Relay Group
Microsoft Security Bulletin (MS00-031)
Released May 10, 2000
Affects Microsoft IIS 4.0 and 5.0
Reference http://www.microsoft.com/technet/security/bulletin/fq00-031.asp
Problem
- The bulletin is related with two security vulnerabilities that are unrelated except by virtue of the fact
that both exist in the ISAPI extension that provides web-based password administration via .HTR
scripts.
- The "Undelimited .HTR Request" vulnerability is a denial of service vulnerability. If a malicious
user provided a password change request that was missing an expected delimiter, the algorithm
would conduct an unbounded search. This would prevent it from servicing additional .HTR
requests, and could also slow the overall response of the server.
- The ".HTR File Fragment Reading" vulnerability could allow fragments of certain types of files to
be read by providing a malformed request that would cause the .HTR processing to be applied to
them. However, the vulnerability could only be exploited under extremely restrictive conditions,
and the most valuable data in the files would be the least likely to actually appear in the fragments
sent to the user.
- Neither of these vulnerabilities would allow data to be added, deleted or changed on the server,
nor would they allow any administrative control on the server to be usurped. Although .HTR files
are used to allow web-based password administration, neither of these vulnerabilities involves any
weakness in password handling. Also, if security best practices have been followed, and
unneeded script mappings have been removed, many customers will have removed the .HTR
script mapping and thus be unaffected by either vulnerability.
SAFER
- Microsoft has released a patch.
FreeBSD Security Advisory SA-00:17: Buffer overflow in libmytinfo
Released May 09, 2000
Affects FreeBSD 3.x
Reference http://www.freebsd.org/
Problem
- libmytinfo allows users to specify an alternate termcap file or entry via the TERMCAP environment
variable, however this is not handled securely and contains an overflowable buffer inside the
library. This is security vulnerability for binaries which are linked against libmytinfo and which are
setuid or setgid (i.e. run with elevated privileges). It may also be vulnerability in other more
obscure situations where a user can exert control over the environment with which another user
runs an ncurses binary.
- FreeBSD 3.x and earlier versions use a very old, customized version of ncurses which is difficult to
update without breaking backwards-compatibility. The update was made for FreeBSD 4.0, but it is
unlikely that 3.x will be updated. However, the ncurses source is currently being audited for further
vulnerabilities.
- Certain setuid/setgid third-party software (including FreeBSD ports/packages) may be vulnerable
to a local exploit yielding privileged resources, such as network sockets, privileged filesystem
access, or outright privileged shell access (including root access).
SAFER
- Remove any setuid or setgid binary which is linked against libmytinfo (including statically linked),
or remove set[ug]id privileges from the file as appropriate.
Allaire Security Bulletin (ASB00-12): Allaire ClusterCATS URL Redirect Vulnerability
Released May 08, 2000
Affects Allaire ClusterCATS 1.0
Reference http://www.allaire.com/
Problem
- While performing a URL redirect, Allaire ClusterCATS may append stale information to the URL
that can contain sensitive information.
SAFER
- Allaire has released a patch, which rectifies this issue.