Release 0004a clears up an error in the original versions reported as vulnerable, as well as provides more detail about the problem. -- RSI.0004a.06-17-98.BSDI.RLOGIND |:::. |::::: |::::. |::::: |::::: |::::. .. :: .. .. :: .. .. .. :: |:::: |:::: |:::: :::::: |::::: |:::: |: |: :: |: |: |:: |: |: :: |: :: |::::: |: |::::: |::::: |::::: Repent Security Incorporated, RSI [ http://www.repsec.com ] *** RSI ALERT ADVISORY *** --- [CREDIT] -------------------------------------------------------------- Mark Zielinski: Research and development, author of advisory. --- [SUMMARY] ------------------------------------------------------------- Announced: June 17, 1998 Report code: RSI.0004a.06-17-98.BSDI.RLOGIND Report title: BSDI rlogind Vulnerability: A buffer overflow exists in rlogind that could allow remote root access on server's running BSDI 2.1 or earlier Vendor status: Has been contacted on 6-17-98 Patch status: No patch currently available Platforms: BSDI 2.0, 2.1 Not affected: FreeBSD (All) NetBSD (All) OpenBSD 2.3 Reference: http://www.repsec.com/advisories.html Impact: If exploited, an attacker could potentially compromise root access on your server --- [DETAILS] ------------------------------------------------------------- Problem: A vulnerability exists in BSDI rlogind that has the potential to allow an attacker to gain remote root access on any server running BSDI 2.1 or earlier with rlogind enabled. This vulnerability occurs as a result of inverse resolution of IP addresses to hostnames. An attacker in control of a DNS server can configure the records for a specific IP address to resolve with a name larger than rlogind can handle. Due to insufficient bounds checking, a buffer overflow can result when rlogind attempts to copy the connecting hostname into a buffer with a predefined size. While overwriting the buffer, the attacker can manipulate the stack and execute their own commands, possibly gaining root access on the server. For more information on this type of attack, point your web browsers to: http://www.repsec.com/bofs.html. --- [FIX] ----------------------------------------------------------------- Solution: Disable rlogind until Berkeley Software Design Inc. can provide a patch. 1. su to the root account 2. kill -9 `ps -aux | grep rlogind | awk '{print $2}'` 3. edit /etc/inetd.conf with your favorite editor 4. place a # in front of any lines beginning with "login" --- [PATCH] --------------------------------------------------------------- Solution: Wait for Berkeley Software Design Inc. to release an official patch. --------------------------------------------------------------------------- Repent Security Incorporated (RSI) 13610 N. Scottsdale Rd. Suite #10-326 Scottsdale, AZ 85254 E-mail: advise@repsec.com WWW: http://www.repsec.com FTP: ftp://ftp.repsec.com --------------------------------------------------------------------------- -----BEGIN PGP PUBLIC KEY BLOCK----- Version: 2.6.2 mQCNAzU6dqAAAAEEAOHt9a5vevjD8ZjsEmncEbFp2U7aeqvPTcF/8FJMilgOVp75 dshXvZixHsYU7flgCNzA7wLIQPWBQBrweLG6dx9gE9e5Ca6yAJxZg8wNsi06tZfP nvmvf6F/7xoWS5Ei4k3YKuzscxlyePNNKws6uUe2ZmwVoB+i3HHT44dOafMhAAUT tBpSZXBTZWMgPGFkdmlzZUByZXBzZWMuY29tPg== =ro8H -----END PGP PUBLIC KEY BLOCK----- Copyright June 1998 RepSec, Inc. The information in this document is provided as a service to customers of RepSec, Inc. Neither RepSec, Inc., nor any of it's employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process contained herein, or represents that its use would not infringe any privately owned rights. Reference herein to any specific commercial products, process, or services by trade name, trademark, manufacturer, or otherwise, does not necessarily constitute or imply its endorsement, recommendation or favoring by RepSec, Inc. The views and opinions of authors express herein do no necessarily state or reflect those of RepSec, Inc., and may not be used for advertising or product endorsement purposes. The material in this alert advisory may be reproduced and distributed, without permission, in whole or in part, by other security incident response teams (both commercial and non-commercial), provided the above copyright is kept intact and due credit is given to RepSec, Inc. This alert advisory may be reproduced and distributed, without permission, in its entirety only, by any person provided such reproduction and/or distribution is performed for non-commercial purposes and with the intent of increasing the awareness of the Internet community. --------------------------------------------------------------------------- RepSec, Inc. are trademarks of RepSec, Inc. All other trademarks are property of their respective holders.