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CVE-2023-20198

CRITICAL KEV CISA Exploitation: ACTIVE
10.0
CVSS 3.1
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.

Metadata

CVE ID
CVE-2023-20198
State
PUBLISHED
Assigner
cisco
Reserved
2022-10-27 18:47 UTC
Published
2023-10-16 15:12 UTC
Last updated
2025-10-21 23:05 UTC
Primary CWE
CWE-420
Unprotected Alternate Channel
Vendor / Product
Cisco / Cisco IOS XE Software
Sources
cve.org  ·  NVD

Severity & Metrics

10.0 CRITICAL CVSS 3.1
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
SSVC — CISA Coordinator
Exploitation
ACTIVE
Automatable
yes
Tech. Impact
total
CISA Known Exploited Vulnerability
Vulnerability name
Cisco IOS XE Web UI Privilege Escalation Vulnerability
Vendor
Cisco
Product
IOS XE Web UI
Added to KEV
2023-10-16
Due date
2023-10-20
Ransomware
Not known
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.
CISA description
Cisco IOS XE Web UI contains a privilege escalation vulnerability in the web user interface that could allow a remote, unauthenticated attacker to create an account with privilege level 15 access. The attacker can then use that account to gain control of the affected device.
Affected products (1)
VendorProductPlatformVersions
Cisco Cisco IOS XE Software — 16.1.1, 16.1.2, 16.1.3, 16.2.1 …
Weakness (CWE)
CWESourceDescription
CWE-420 cna Unprotected Alternate Channel
CVSS scores (1)
ScoreSeverityVersionSourceVector
10.0 CRITICAL 3.1 cna CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
References (1)
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