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_____________________________________________________ The U.S. Department of Energy Computer Incident Advisory Capability ___ __ __ _ ___ / | /_\ / \___ __|__ / \ \___ _____________________________________________________ INFORMATION BULLETIN SATAN password disclosure April 13, 1995 1100 PDT Number F-22 _____________________________________________________________________________ PROBLEM: Unauthorized users may execute commands through SATAN. PLATFORMS: Any system running SATAN. DAMAGE: Commands can be sent to the SATAN HTML server where the commands will be executed with the privileges of the SATAN process. SOLUTION: Upgrade to SATAN 1.1.1 and follow the steps outlined in this bulletin to keep SATAN's password secret. _____________________________________________________________________________ VULNERABILITY Disclosure of SATAN's password along with descriptions ASSESSMENT: in the current release of SATAN provided adequate information that knowledgable users could execute commands through SATAN. _____________________________________________________________________________ Information about SATAN password disclosure Earlier releases of SATAN, prior to version 1.1, use a 32-bit "quasi-random" number for the password. If the password is disclosed, unauthorized users can send commands to the SATAN HTML server where the commands will be executed with the privileges of the SATAN process which typically runs as root. Some of the ways SATAN's password can be disclosed are: 1) Visiting another web site from the SATAN client, either by directly entering the URL or by going to a site on their local hotlist. Some clients send the last document visited in the Referer field that may include SATAN's password. 2) Systems running SATAN that also have their filesystem containing SATAN's directory exported. Unauthorized users can then read files within SATAN's directory and obtain SATAN's password. 3) Permitting unauthorized users to connect to the X server when running SATAN. In addition to capturing the screen contents, some HTML clients display the current URL, which in SATAN's case contains the password. Steps to protect SATAN password require that X Windows and NFS be used in a secure manner. CIAC recommends that users of SATAN: Avoid using the xhost mechanism. - Any user from the authorized host can connect to the X server. Avoid running X applications with output to a remote display. - X magic cookie information can be captured from the network while X clients connect to the remote display. Avoid running SATAN with output to a remote display. - SATAN password information can be captured from the network while URL information is shown on the remote display. Avoid sharing your home directory. - X magic cookie information (e.g., .Xauthority) may be captured from the network while the X software accesses that file. Avoid sharing the SATAN directories with other hosts. - SATAN password information may be captured from the network. Use a browser that does not send the Referer field (Netscape and Lynx send the Referer field) and/or do not connect to other Web servers from SATAN's client. - Web servers can be modified to log Referer fields which contain SATAN's password. Additional checks have been added to SATAN version 1.1.1 in the event SATAN's password has been compromised. These new features include: 1) SATAN displays a warning and advises the user to not contact other HTML servers from within a SATAN session. 2) SATAN rejects requests that appear to come from hosts other than the one it is running on, that refer to resources outside its own HTML tree, or that contain unexpected data. example: SATAN password from unauthorized client: 128.115.19.53 3) SATAN terminates with a warning when it finds a valid SATAN password in an illegal request. example: Illegal URL: /7a1e696b41ecb710936dbc317b9122f7/ \ /home/satan-1.1.1/bad.html \ received from: 128.115.19.53 The current vulnerabilities that SATAN version 1.1.1 checks for are: 1) FTP vulnerabilities - Root access via the wuarchive FTPD server 2) NFS export to unprivileged programs - NFS server executes requests from unprivileged user programs. 3) NFS export via portmapper - NFS file exports via the portmapper 4) NIS password file access - NIS password file access by arbitrary hosts 5) REXD access - REXD remote access from arbitrary hosts 6) SATAN password disclosure - SATAN password disclosure via flawed HTML clients or environmental problems 7) Sendmail vulnerabilities - Assorted sendmail vulnerabilities 8) TFTP file access - File access via the TFTP service 9) remote shell access - Remote shell/remote login access from arbitrary hosts 10) unrestricted NFS export - File systems exported via NFS to arbitrary hosts 11) unrestricted X server access - X server access from arbitrary hosts 12) unrestricted modem - A live and potentially unrestricted modem has been detected 13) writable FTP home directory - FTP home directory is writable for anonymous users ------------------------------------------------------------------------------ CIAC would like to thank CERT/CC, Matthew Gray, Dan Farmer and Wietse Venema for the information contained in this bulletin. ------------------------------------------------------------------------------ CIAC is the computer security incident response team for the U.S. Department of Energy. Services are available free of charge to DOE and DOE contractors. DOE and DOE contractor sites can contact CIAC at: Voice: 510-422-8193 FAX: 510-423-8002 STU-III: 510-423-2604 E-mail: ciac@llnl.gov For DOE and DOE contract site emergencies only, call 1-800-SKYPAGE (1-800-759-7243) and enter PIN number 8550070 (primary) or 8550074 (secondary). Previous CIAC notices, anti-virus software, and other information are available via WWW (http://ciac.llnl.gov/) and anonymous FTP from ciac.llnl.gov (IP address 128.115.19.53). CIAC has several self-subscribing mailing lists for electronic publications: 1. CIAC-BULLETIN for Advisories, highest priority - time critical information, and Bulletins, important computer security information; 2. CIAC-NOTES for Notes, a collection of computer security articles; 3. SPI-ANNOUNCE for official news about Security Profile Inspector (SPI) software updates, new features, distribution and availability; 4. 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Send to: ciac-listproc@llnl.gov not to: ciac@llnl.gov e.g., subscribe ciac-notes O'Hara, Scarlett 404-555-1212 x36 subscribe ciac-bulletin O'Hara, Scarlett 404-555-1212 x36 You will receive an acknowledgment containing address and initial PIN, and information on how to change either of them, cancel your subscription, or get help. _____________________________________________________________________________ PLEASE NOTE: Many users outside of the DOE and ESnet computing communities receive CIAC bulletins. If you are not part of these communities, please contact your agency's response team to report incidents. Your agency's team will coordinate with CIAC. The Forum of Incident Response and Security Teams (FIRST) is a world-wide organization. A list of FIRST member organizations and their constituencies can be obtained by sending E-mail to first-request@first.org with an empty subject line and a message body containing the line: send first-contacts. 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