Vulnerability identifier: #VU80775

Vulnerability risk: Low

CVSSv3.1: 5.6 [CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2023-20135

CWE-ID: CWE-367

Exploitation vector: Local

Exploit availability: No

Vulnerable software:
Cisco IOS XR
Operating systems & Components / Operating system
Cisco 8000 Series Routers
Hardware solutions / Routers & switches, VoIP, GSM, etc
Cisco Network Convergence System 540 Series Routers
Hardware solutions / Routers & switches, VoIP, GSM, etc
Network Convergence System 5700 Series
Other software / Other software solutions

Vendor: Cisco Systems, Inc

Description

The vulnerability allows a local user to execute arbitrary code on the system.

The vulnerability exists due to a time-of-check, time-of-use (TOCTOU) race condition when an install query regarding an ISO image is performed during an install operation that uses an ISO image. A local administrator can execute arbitrary code on target system.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Cisco IOS XR: 7.5.2 - 7.7.0

Cisco 8000 Series Routers: All versions

Cisco Network Convergence System 540 Series Routers: All versions

Network Convergence System 5700 Series: All versions

---

External links
http://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-lnt-L9zOkBz5

---

Q & A

Can this vulnerability be exploited remotely?

No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.