MIME-compliant email client attachment buffer overflow (POP_Filename_Overflow)

About this signature or vulnerability

Proventia Network IPS, RealSecure Desktop Protector 3.6, Proventia Server IPS for Linux technology, IBM Security Server Protection for Windows, Proventia Network MFS, Proventia-G 1.1 and earlier, Proventia Network IDS, Proventia Desktop, BlackICE Agent for Server, RealSecure Guard, RealSecure Sentry, BlackICE PC Protection, BlackICE Server Protection, RealSecure Network, RealSecure Server Sensor, Virtual Server Protection for Vmware:

This signature detects a long MIME filename transferred over the POP3 protocol, which may indicate an attacker's attempt to overflow a buffer and execute code on a mail server. The signature triggers on the configurable threshold 'pam.mime.filename.limit' (default 256).

This signature detects a long MIME filename. This may indicate an attacker's attempt to overflow a buffer and execute code on a server.


False positives

Proventia Network IPS, Proventia Server IPS for Linux technology, IBM Security Server Protection for Windows, Proventia Network MFS, Proventia-G 1.1 and earlier, Proventia Network IDS, Proventia Desktop, RealSecure Network, RealSecure Server Sensor, Virtual Server Protection for Vmware: Non-malicious long filenames can be somewhat common in some environments, and may cause this signature to trigger.

Default risk level

High risk vulnerability  High

Sensors that have this signature

Proventia Network IPS: 2.0, RealSecure Desktop Protector 3.6: baseline, RealSecure Desktop: baseline, Proventia Server IPS for Linux technology: 1.0, IBM Security Server Protection for Windows: 2.1.14.2400, IBM Security Server Protection for Windows: 1.0.914.0, Proventia Network MFS: 1.0, Proventia-G 1.1 and earlier: G Series, Proventia Network IDS: A Series, Proventia Desktop: 8.0.614.1, BlackICE Agent for Server: 3.6, RealSecure Guard: 3.6, RealSecure Sentry: 3.6, BlackICE PC Protection: 3.6.cbd, BlackICE Server Protection: 3.6.cbd, RealSecure Network: 7.0, RealSecure Desktop Protector: 3.6, RealSecure Server Sensor: 7.0, Virtual Server Protection for Vmware: 1.0

Systems affected

Various vendors Any application, Unix Unix, Microsoft Windows 95, Microsoft Windows NT: 4.0, Microsoft Windows 98

Type

Unauthorized Access Attempt

Vulnerability description

Many popular MIME-compliant email clients are vulnerable to a denial of service attack caused by a buffer overflow in the handling of certain headers. By sending a specially-crafted mail message, an attacker can overflow a buffer and crash another user's client. It may be possible to use this vulnerability to execute arbitrary commands on the victim's computer.

How to remove this vulnerability

Upgrade to the latest version of Sendmail (8.9.1a or later), as listed in CERT Advisory CA-1998-10. See References.

For Microsoft Outlook:
Apply the appropriate patch for your system, as listed in Microsoft Security Bulletin MS98-008. See References.

For other distributions:
Contact your vendor for upgrade or patch information.

References

Microsoft Security Bulletin MS98-008
Update Available For Long file name Security Issue
http://www.microsoft.com/technet/security/bulletin/ms98-008.mspx

AusCERT Advisory AA-98.04
Sendmail, Inc. Patch for MIME Buffer Overflows
ftp://ftp.auscert.org.au/pub/auscert/advisory/AA-98.04.sendmail.MIME.patches

Sendmail 8.9.1a patch
MIME Buffer Overflows
ftp://ftp.sendmail.org/pub/sendmail/past-releases/sendmail.8.9.1a.patch.README

CERT Advisory CA-1998-10
Buffer Overflow in MIME-aware Mail and News Clients
http://www.cert.org/advisories/CA-1998-10.html

Sun Microsystems, Inc. Security Bulletin #00175
mailtool
http://sunsolve.sun.com/pub-cgi/retrieve.pl?doctype=coll&doc=secbull/175&type=0&nav=sec.sba

CERT Vulnerability Note VU#5648
Buffer Overflows in various email clients
http://www.kb.cert.org/vuls/id/5648

Netscape Security Update, August 14, 1998
Long Filename Mail Vulnerability
http://home.netscape.com/security/notes/previous/longfile.html

CIAC Information Bulletin I-077b
Mime Name Vulnerability in Outlook and Messenger
http://www.ciac.org/ciac/bulletins/i-077b.shtml

AusCERT Advisory AA-98.02
Microsoft Outlook Overrun Vulnerability
ftp://ftp.auscert.org.au/pub/auscert/advisory/AA-98.02.Outlook.buffer.overflow

ISS X-Force
MIME-compliant email client attachment buffer overflow
http://www.iss.net/security_center/static/1217.php

CVE
CVE-1999-0004
http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-1999-0004