Actively exploited · Published Oct 16, 2023 · Assigned by cisco
CVE-2023-20198
Critical 10.0 Exploited
In plain English
A critical-severity security flaw in Cisco IOS XE Software from Cisco. Attackers are actively exploiting it in the wild (listed by CISA on October 16, 2023). The chance it is exploited in the next 30 days is estimated at 99.6% (higher than 99.9% of all known vulnerabilities). Ready-made attack tooling exists: Metasploit, Nuclei, public proof-of-concept code. Verify that instances of Cisco IOS XE Web UI are in compliance with BOD 23-02 and apply mitigations per vendor instructions. For affected products (Cisco IOS XE Web UI exposed to the internet or to untrusted networks), follow vendor instructions to determine if a system may have been compromised and immediately report positive findings to CISA.
CISA guidance
Verify that instances of Cisco IOS XE Web UI are in compliance with BOD 23-02 and apply mitigations per vendor instructions. For affected products (Cisco IOS XE Web UI exposed to the internet or to untrusted networks), follow vendor instructions to determine if a system may have been compromised and immediately report positive findings to CISA.
Federal agencies must remediate by Oct 20, 2023.
Official description
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. 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.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Cisco | Cisco IOS XE Software | 16.1.116.1.216.1.316.2.116.2.216.3.116.3.216.3.3 |
Weakness: CWE-420 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H