Vulnerability in Cisco iOS Xe Software

CVE-2023-20198

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.

EPSS: 0.996 (99.9th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 10.0 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H.

Affected products

Weakness classification (CWE)

CISA KEV (Known Exploited Vulnerabilities)

This CVE is on the CISA KEV catalog, added on . CISA KEV inclusion means CISA has confirmed in-the-wild exploitation; US federal agencies are required to remediate within a published due date.

BOD 22-01 due date: .

Required action: 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.

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2023-20198?
CVE-2023-20198 is a critical-severity vulnerability in Cisco iOS Xe Software, classified under Unprotected Alternate Channel. CVSS score: 10.0/10. Published 2023-10-16.
How severe is CVE-2023-20198?
Critical severity. CVSS v3 base score is 10.0 out of 10.
Is CVE-2023-20198 known to be exploited?
Yes. CVE-2023-20198 is listed in the CISA Known Exploited Vulnerabilities catalog (added 2023-10-16), indicating it is being actively exploited. 110 public proof-of-concept repositories are indexed.