Cisco IOS XR Local Authenticated TOCTOU Code Exec Vulnerability
CVE-2023-20135 Published on September 13, 2023
A vulnerability in Cisco IOS XR Software image verification checks could allow an authenticated, local attacker to execute arbitrary code on the underlying operating system. This vulnerability is 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. An attacker could exploit this vulnerability by modifying an ISO image and then carrying out install requests in parallel. A successful exploit could allow the attacker to execute arbitrary code on an affected device.
Vulnerability Analysis
CVE-2023-20135 can be exploited with local system access, and requires user privileges. This vulnerability is consided to have a high level of attack complexity. The potential impact of an exploit of this vulnerability is considered to have a high impact on confidentiality and integrity, and no impact on availability.
Weakness Type
Improper Verification of Cryptographic Signature
The software does not verify, or incorrectly verifies, the cryptographic signature for data.
Products Associated with CVE-2023-20135
stack.watch emails you whenever new vulnerabilities are published in Cisco Ios Xr or Cisco Internetwork Operating System (IOS). Just hit a watch button to start following.
Affected Versions
Cisco IOS XR Software:- Version 7.5.3 is affected.
- Version 7.5.2 is affected.
- Version 7.5.4 is affected.
- Version 7.7.1 is affected.
- Version 7.7.2 is affected.
- Version 7.7.21 is affected.
- Version 7.8.1 is affected.
- Version 7.8.2 is affected.
- Version 7.9.1 is affected.
- Version 7.9.2 is affected.
Exploit Probability
EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.