Protect yourself against future threats.
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA256 =========================================================================== AUSCERT External Security Bulletin Redistribution ESB-2020.3274 Cisco IOS XE Software Web UI vulnerabilities 25 September 2020 =========================================================================== AusCERT Security Bulletin Summary --------------------------------- Product: Cisco IOS XE Software Web UI Publisher: Cisco Systems Operating System: Cisco Impact/Access: Denial of Service -- Existing Account Unauthorised Access -- Existing Account Resolution: Patch/Upgrade CVE Names: CVE-2020-3516 CVE-2020-3400 Original Bulletin: https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-webui-auth-bypass-6j2BYUc7 https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-WEB-UI-exNFmcPO Comment: This bulletin contains two (2) Cisco Systems security advisories. - --------------------------BEGIN INCLUDED TEXT-------------------- Cisco IOS XE Software Web UI Authorization Bypass Vulnerability Priority: High Advisory ID: cisco-sa-webui-auth-bypass-6j2BYUc7 First Published: 2020 September 24 16:00 GMT Version 1.0: Final Workarounds: No workarounds available Cisco Bug IDs: CSCva31948 CVE-2020-3400 CWE-862 CVSS Score: 8.8 AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:X/RL:X/RC:X Summary o A vulnerability in the web UI feature of Cisco IOS XE Software could allow an authenticated, remote attacker to utilize parts of the web UI for which they are not authorized. The vulnerability is due to insufficient authorization of web UI access requests. An attacker could exploit this vulnerability by sending a crafted HTTP request to the web UI. A successful exploit could allow the attacker to utilize parts of the web UI for which they are not authorized. This could allow a Read-Only user to perform actions of an Admin user. 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-webui-auth-bypass-6j2BYUc7 This advisory is part of the September 24, 2020, release of the Cisco IOS and IOS XE Software Security Advisory Bundled Publication, which includes 25 Cisco Security Advisories that describe 34 vulnerabilities. For a complete list of the advisories and links to them, see Cisco Event Response: September 2020 Semiannual Cisco IOS and IOS XE Software Security Advisory Bundled Publication . Affected Products o Vulnerable Products This vulnerability affects Cisco devices that are running a vulnerable release of Cisco IOS XE Software with the HTTP Server feature enabled. The default state of the HTTP Server feature in Cisco IOS XE Software is platform dependent. For information about which Cisco software releases are vulnerable, see the Fixed Software section of this advisory. Determine the HTTP Server Configuration To determine whether the HTTP Server feature is enabled for a device, log in to the device and use the show running-config | include ip http server| secure|active command in the CLI to check for the presence of the ip http server command or the ip http secure-server command in the global configuration. If either command is present and configured, the HTTP Server feature is enabled for the device. The following example shows the output of the show running-config | include ip http server|secure|active command for a device that has the HTTP Server feature enabled: Router# show running-config | include ip http server|secure|active ip http server ip http secure-server Note: The presence of either command or both commands in the device configuration indicates that the web UI feature is enabled. If the ip http server command is present and the configuration also contains ip http active-session-modules none , the vulnerability is not exploitable over HTTP. If the ip http secure-server command is present and the configuration also contains ip http secure-active-session-modules none , the vulnerability is not exploitable over HTTPS. Products Confirmed Not Vulnerable Only products listed in the Vulnerable Products section of this advisory are known to be affected by this vulnerability. Cisco has confirmed that this vulnerability does not affect the following Cisco products: IOS Software IOS XR Software NX-OS Software Workarounds o There are no workarounds that address this vulnerability. Disabling the HTTP Server feature eliminates the attack vector for this vulnerability and may be a suitable mitigation until affected devices can be upgraded. To disable the HTTP Server feature, use the no ip http server or no ip http secure-server command in global configuration mode. If both the HTTP server and HTTPS server are in use, both commands are required to disable the HTTP Server feature. Fixed Software o Cisco has released free software updates that address the vulnerability described in this advisory. Customers may only install and expect support for software versions and feature sets for which they have purchased a license. By installing, downloading, accessing, or otherwise using such software upgrades, customers agree to follow the terms of the Cisco software license: https://www.cisco.com/c/en/us/products/ end-user-license-agreement.html Additionally, customers may only download software for which they have a valid license, procured from Cisco directly, or through a Cisco authorized reseller or partner. In most cases this will be a maintenance upgrade to software that was previously purchased. Free security software updates do not entitle customers to a new software license, additional software feature sets, or major revision upgrades. 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. Customers Without Service Contracts Customers who purchase directly from Cisco but do not hold a Cisco service contract and customers who make purchases through third-party vendors but are unsuccessful in obtaining fixed software through their point of sale should obtain upgrades by contacting the Cisco TAC: https://www.cisco.com/c /en/us/support/web/tsd-cisco-worldwide-contacts.html Customers should have the product serial number available and be prepared to provide the URL of this advisory as evidence of entitlement to a free upgrade. Cisco IOS and IOS XE Software To help customers determine their exposure to vulnerabilities in Cisco IOS and IOS XE Software, Cisco provides the Cisco Software Checker to identify any Cisco Security Advisories that impact a specific software release and the earliest release that fixes the vulnerabilities described in each advisory ("First Fixed"). If applicable, the tool also returns the earliest release that fixes all the vulnerabilities described in all the advisories identified ("Combined First Fixed"). Customers can use the Cisco Software Checker to search advisories in the following ways: Choose the software and one or more releases Upload a .txt file that includes a list of specific releases Enter the output of the show version command After initiating a search, customers can customize the search to include all Cisco Security Advisories, a specific advisory, or all advisories in the most recent bundled publication. Customers can also use the following form to determine whether a release is affected by any Cisco Security Advisory by entering a Cisco IOS or IOS XE Software release-for example, 15.1(4)M2 or 3.13.8S : [ ] [Check] By default, the Cisco Software Checker includes results only for vulnerabilities that have a Critical or High Security Impact Rating (SIR). To include results for Medium SIR vulnerabilities, customers can use the Cisco Software Checker on Cisco.com and check the Medium check box in the drop-down list under Impact Rating when customizing a search. For a mapping of Cisco IOS XE Software releases to Cisco IOS Software releases, refer to the Cisco IOS XE 2 Release Notes , Cisco IOS XE 3S Release Notes , or Cisco IOS XE 3SG Release Notes , depending on the Cisco IOS XE Software release. 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 internal security testing. 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. Related to This Advisory o Cisco Event Response: September 2020 Semiannual Cisco IOS and IOS XE Software Security Advisory Bundled Publication URL o https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/ cisco-sa-webui-auth-bypass-6j2BYUc7 Revision History o +----------+---------------------------+----------+--------+--------------+ | Version | Description | Section | Status | Date | +----------+---------------------------+----------+--------+--------------+ | 1.0 | Initial public release. | - | Final | 2020-SEP-24 | +----------+---------------------------+----------+--------+--------------+ - -------------------------------------------------------------------------------- Cisco IOS XE Software Web UI Improper Input Validation Vulnerability Priority: Medium Advisory ID: cisco-sa-WEB-UI-exNFmcPO First Published: 2020 September 24 16:00 GMT Version 1.0: Final Workarounds: No workarounds available Cisco Bug IDs: CSCvr73955 CVE-2020-3516 CWE-20 CVSS Score: 4.3 AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L/E:X/RL:X/RC:X Summary o A vulnerability in the web server authentication of Cisco IOS XE Software could allow an authenticated, remote attacker to crash the web server on the device. The vulnerability is due to insufficient input validation during authentication. An attacker could exploit this vulnerability by entering unexpected characters during a valid authentication. A successful exploit could allow the attacker to crash the web server on the device, which must be manually recovered by disabling and re-enabling the web server. 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-WEB-UI-exNFmcPO Affected Products o Vulnerable Products At the time of publication, this vulnerability affected Cisco IOS XE Software releases earlier than releases 16.9.6, 16.12.2, or 17.1.1. For information about which Cisco software releases are vulnerable, see the Fixed Software section of this advisory. Determine the HTTP Server Configuration To determine whether the HTTP Server feature is enabled for a device, log in to the device and use the show running-config | include ip http server| secure|active command in the CLI to check for the presence of the ip http server command or the ip http secure-server command in the global configuration. If either command is present and configured, the HTTP Server feature is enabled for the device. The following example shows the output of the show running-config | include ip http server|secure|active command for a device that has the HTTP Server feature enabled: Router# show running-config | include ip http server|secure|active ip http server ip http secure-server Note: The presence of either command or both commands in the device configuration indicates that the web UI feature is enabled. If the ip http server command is present and the configuration also contains ip http active-session-modules none , the vulnerability is not exploitable over HTTP. If the ip http secure-server command is present and the configuration also contains ip http secure-active-session-modules none , the vulnerability is not exploitable over HTTPS. Products Confirmed Not Vulnerable Only products listed in the Vulnerable Products section of this advisory are known to be affected by this vulnerability. Cisco has confirmed that this vulnerability does not affect the following Cisco products: IOS Software IOS XR Software NX-OS Software Details o When this vulnerability is exploited, only the web server functionality is broken. General traffic through the device is unaffected. Workarounds o There are no workarounds that address this vulnerability. Disabling the HTTP Server feature eliminates the attack vector for this vulnerability and may be a suitable mitigation until affected devices can be upgraded. To disable the HTTP Server feature, use the no ip http server or no ip http secure-server command in global configuration mode. If both the HTTP server and HTTPS server are in use, both commands are required to disable the HTTP Server feature. Fixed Software o When considering software upgrades , customers are advised to regularly consult the advisories for Cisco products, which are available from the Cisco Security Advisories 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. Cisco IOS and IOS XE Software To help customers determine their exposure to vulnerabilities in Cisco IOS and IOS XE Software, Cisco provides the Cisco Software Checker to identify any Cisco Security Advisories that impact a specific software release and the earliest release that fixes the vulnerabilities described in each advisory ("First Fixed"). If applicable, the tool also returns the earliest release that fixes all the vulnerabilities described in all the advisories identified ("Combined First Fixed"). Customers can use the Cisco Software Checker to search advisories in the following ways: Choose the software and one or more releases Upload a .txt file that includes a list of specific releases Enter the output of the show version command After initiating a search, customers can customize the search to include all Cisco Security Advisories, a specific advisory, or all advisories in the most recent bundled publication. Customers can also use the following form to determine whether a release is affected by any Cisco Security Advisory by entering a Cisco IOS or IOS XE Software release-for example, 15.1(4)M2 or 3.13.8S : [ ] [Check] By default, the Cisco Software Checker includes results only for vulnerabilities that have a Critical or High Security Impact Rating (SIR). To include results for Medium SIR vulnerabilities, customers can use the Cisco Software Checker on Cisco.com and check the Medium check box in the drop-down list under Impact Rating when customizing a search. For a mapping of Cisco IOS XE Software releases to Cisco IOS Software releases, refer to the Cisco IOS XE 2 Release Notes , Cisco IOS XE 3S Release Notes , or Cisco IOS XE 3SG Release Notes , depending on the Cisco IOS XE Software release. 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 internal security testing. 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-WEB-UI-exNFmcPO Revision History o +----------+---------------------------+----------+--------+--------------+ | Version | Description | Section | Status | Date | +----------+---------------------------+----------+--------+--------------+ | 1.0 | Initial public release. | - | Final | 2020-SEP-23 | +----------+---------------------------+----------+--------+--------------+ - --------------------------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 iQIVAwUBX20nGONLKJtyKPYoAQg8/A//cI/MjO6ku/1lCRWWkk/TKA9zCEBALw3g oSIm/yV43gVzRaAgbhoH8oAAyE00PEXyuy17VoRKlw4WcJhxORaYzC/o1vZqpJcH M1YsExEbS+C6DDP3l5Ilvxrke5a5zg2zcitA25qoWrDdjfCMOl2f0Rhs4cOZp5Zp SEGXIcIz1jDDfkyf8abA9LaWY9bnFn/Ct9q1Yz0Ua9YJbBczQBivNPycdgheoZom uB/675HVuks5s6D0s9XeiFKm5ndOcGQEux50zcDG3iplCtXTfB18eUP+ZsU5N0Ko C8RIZ6WLyCx1BCvW4t6mp1UqxALAZTEPe1xOUaH+s6T6ORBgREZ4HGrgwcR3W6Eb 1nAeFzbiw1lHrTyUIvhHJRApdDetwElFHXzl+RSc1k8M6ap+QwvTyvtbfH7Uk4Eq hrdsf05qNp84air9NsSPwb2vaCynQUCoyYMtrLUfrKCJVUadD27tmqtQVxYvwm+q joglymqlvxBJ1eaEpHVMFmc1PF66Hy9oOF0UQEgvZAXiR4bqaKZ4kPdJ1MmG27H5 7QaZRsUIur1Zn4OCI4hD4WPlDuFpblcnRlQSyDDwZsmRfENcO/Z/bEwx83m9xXkb GOtwYpsx8oEe950PVWJUr+dvs2IwPgPujtVyISiN2c7t2jRocALmwu0aeEn3wKGe SV30xqU+GM4= =HHa8 -----END PGP SIGNATURE-----