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-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA256 =========================================================================== AUSCERT External Security Bulletin Redistribution ESB-2019.0355 Cisco Web Security Appliance Decryption Policy Bypass Vulnerability 7 February 2019 =========================================================================== AusCERT Security Bulletin Summary --------------------------------- Product: Cisco Web Security Appliance Publisher: Cisco Systems Operating System: Cisco Impact/Access: Unauthorised Access -- Remote/Unauthenticated Resolution: Patch/Upgrade CVE Names: CVE-2019-1672 Original Bulletin: https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20190206-wsa-bypass - --------------------------BEGIN INCLUDED TEXT-------------------- Cisco Security Advisory Cisco Web Security Appliance Decryption Policy Bypass Vulnerability Advisory ID: cisco-sa-20190206-wsa-bypass First Published: 2019 February 6 16:00 GMT Version 1.0: Final Workarounds: No workarounds available Cisco Bug IDs: CSCvm91630 CVE-2019-1672 CWE-400 CVSS Score: Base 5.8 CVSS: 3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N/E:X/RL:X/RC:X Summary o A vulnerability in the Decryption Policy Default Action functionality of the Cisco Web Security Appliance (WSA) could allow an unauthenticated, remote attacker to bypass a configured drop policy and allow traffic onto the network that should have been denied. The vulnerability is due to the incorrect handling of SSL-encrypted traffic when Decrypt for End-User Notification is disabled in the configuration. An attacker could exploit this vulnerability by sending a SSL connection through the affected device. A successful exploit could allow the attacker to bypass a configured drop policy to block specific SSL connections. Cisco has released software updates that address this vulnerability. There are no workarounds that address this vulnerability. This advisory is available at the following link: https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/ cisco-sa-20190206-wsa-bypass Affected Products o Vulnerable Products This vulnerability affects Cisco Web Security Appliance. For information about affected software releases, consult the Cisco bug ID(s) at the top of this advisory. Products Confirmed Not Vulnerable Only products listed in the Vulnerable Products section of this advisory are known to be affected by this vulnerability. Details o To determine if Decrypt for End-User Notification is Disabled on the WSA, an administrator can do the following: - Navigate to Security Service > HTTPS Proxy > Decrypt for End-User Notification. - Verify that the Decrypt for End-User Notification configuration setting is Disabled. Workarounds o There are no workarounds that address this vulnerability. Fixed Software o For information about fixed software releases, consult the Cisco bug ID(s) at the top of this advisory. When considering software upgrades, customers are advised to regularly consult the advisories for Cisco products, which are available from the Cisco Security Advisories and Alerts page, to determine exposure and a complete upgrade solution. In all cases, customers should ensure that the devices to be upgraded contain sufficient memory and confirm that current hardware and software configurations will continue to be supported properly by the new release. If the information is not clear, customers are advised to contact the Cisco Technical Assistance Center (TAC) or their contracted maintenance providers. Exploitation and Public Announcements o The Cisco Product Security Incident Response Team (PSIRT) is not aware of any public announcements or malicious use of the vulnerability that is described in this advisory. Source o This vulnerability was found during the resolution of a Cisco TAC support case. Cisco Security Vulnerability Policy o To learn about Cisco security vulnerability disclosure policies and publications, see the Security Vulnerability Policy. This document also contains instructions for obtaining fixed software and receiving security vulnerability information from Cisco. URL o https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/ cisco-sa-20190206-wsa-bypass Revision History o +---------+---------------------------+---------+--------+-------------------+ | Version | Description | Section | Status | Date | +---------+---------------------------+---------+--------+-------------------+ | 1.0 | Initial public release. | -- | Final | 2019-February-06 | +---------+---------------------------+---------+--------+-------------------+ - --------------------------END INCLUDED TEXT-------------------- You have received this e-mail bulletin as a result of your organisation's registration with AusCERT. The mailing list you are subscribed to is maintained within your organisation, so if you do not wish to continue receiving these bulletins you should contact your local IT manager. If you do not know who that is, please send an email to auscert@auscert.org.au and we will forward your request to the appropriate person. NOTE: Third Party Rights 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 follow or act on information or advice contained in this security bulletin is the responsibility of each user or organisation, and should be considered in accordance with your organisation's site policies and procedures. AusCERT takes no responsibility for consequences which may arise from following or acting on information or advice contained in this security bulletin. 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 author's website 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: https://www.auscert.org.au/bulletins/ =========================================================================== Australian Computer Emergency Response Team The University of Queensland Brisbane Qld 4072 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 member emergencies only. =========================================================================== -----BEGIN PGP SIGNATURE----- Comment: http://www.auscert.org.au/render.html?it=1967 iQIVAwUBXFub1maOgq3Tt24GAQhbfBAAyOjPSFFgHpIJvpU8ENd9XrFQMTa7M/2O 1389OUstDDFgUkvR20R5gQkOCze+ZFSmZYwfGuhqLvjTE8VfJIedTFDRSIw9i24v Gr1r5144wmBLocTvG76JKlN9L51QYF7w1jzL126TGxqWI6yfijXw+GJq4R7i1s/L J5tIAIbNfC0Ks8y34ijI9huYTcjffsZSoJBdaYP2iqUzxx93uG+8gs6WXHhvRIJJ 1Ga3DW4eK0jIXJyrBS+D5Zk7+uDzkAG8Y1u7r9A8wZIPaRA8FTwKM7gTMmiczuFs VEiGyWROzlmKMM7rT2eYRDN2G7SiCTZ4f1Xo6AKviBfdi/Ss7JCMJsVxBpmSsfRj FQwSpRpWPMUcNOtrJqYgJ5+fO+yQYgq1W2S3wdE9xvbzxhmax7wPCgHHoW8JjeSd iwpvF7CPkr1SRzmfyWJ9gvvwdWIIZE0Tz8k6+7TLYhHFd07PX76xXP+MXxQgXUfG xZcEyQ1fH3+5NMHNudYFf2WrcfFj2gMAK/1TI0Vymx6PdtNiXJEpfIB51VcjuLpZ VcuGridt/CwTuOFT2PqW9xW6PFHlrQaik4wrj/QBa2WNjGfC5gNFMW/CkgAf6c5d DPtRz5FKhqj/3wIdFlo1ARPRsCUdrIjFEozAsmqKggYb+Njkhkyeoz6gvp0ONeJT XPoaSinlOKw= =TbS5 -----END PGP SIGNATURE-----