Exploitation Indicators Of CVE-2023-20198

calendar Oct 26, 2023 · attack.privilege_escalation attack.initial_access detection.emerging_threats  ·
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Detecting exploitation indicators of CVE-2023-20198 a privilege escalation vulnerability in Cisco IOS XE Software Web UI.

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 1title: Exploitation Indicators Of CVE-2023-20198
 2id: 2ece8816-b7a0-4d9b-b0e8-ae7ad18bc02b
 3status: experimental
 4description: Detecting exploitation indicators of CVE-2023-20198 a privilege escalation vulnerability in Cisco IOS XE Software Web UI.
 5references:
 6    - https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-iosxe-webui-privesc-j22SaA4z
 7    - https://www.thestack.technology/security-experts-call-for-incident-response-exercises-after-mass-cisco-device-exploitation/
 8author: Lars B. P. Frydenskov (Trifork Security)
 9date: 2023/10/20
10tags:
11    - attack.privilege_escalation
12    - attack.initial_access
13    - detection.emerging_threats
14logsource:
15    product: cisco
16    service: syslog
17    definition: 'Requirements: Cisco IOS XE system logs needs to be configured and ingested'
18detection:
19    keyword_event:
20        - '%WEBUI-6-INSTALL_OPERATION_INFO:'
21        - '%SYS-5-CONFIG_P:'
22        - '%SEC_LOGIN-5-WEBLOGIN_SUCCESS:'
23    keyword_user:
24        - 'cisco_tac_admin'
25        - 'cisco_support'
26        - 'cisco_sys_manager'
27    condition: keyword_event and keyword_user
28falsepositives:
29    - Rare false positives might occur if there are valid users named "cisco_tac_admin" or "cisco_support", which are not created by default or CISCO representatives
30level: high

References

  • Multiple Vulnerabilities in Cisco IOS XE Software Web UI Feature

    Cisco is providing an update for the ongoing investigation into observed exploitation of the web UI feature in Cisco IOS XE Software. We are updating the list of fixed releases and adding the Software Checker. Fix information can be found in the Fixed Software section of this advisory. Our investigation has determined that the actors exploited two previously unknown issues. The attacker first exploited CVE-2023-20198 to gain initial access and issued a privilege 15 command to create a local user and password combination. This allowed the user to log in with normal user access. The attacker then exploited another component of the web UI feature, leveraging the new local user to elevate privilege to root and write the implant to the file system. Cisco has assigned CVE-2023-20273 to this issue. CVE-2023-20198 has been assigned a CVSS Score of 10.0. CVE-2023-20273 has been assigned a CVSS Score of 7.2. Both of these CVEs are being tracked by CSCwh87343. For steps to close the attack vector for these vulnerabilities, see the Recommendations section of this advisory. This advisory is available at the following link:https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-iosxe-webui-privesc-j22SaA4z


    Read More

  • Incident response exercises urged after mass Cisco device exploitation

    Cisco says patch pending October 22 for what transpires to have been two discrete zero days...


    Read More

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