Vulnerability in Cisco iOS
CVE-2021-1620
A vulnerability in the Internet Key Exchange Version 2 (IKEv2) support for the AutoReconnect feature of Cisco IOS Software and Cisco IOS XE Software could allow an authenticated, remote attacker to exhaust the free IP addresses from the assigned local pool. This vulnerability occurs because the code does not release the allocated IP address under certain failure conditions. An attacker could exploit this vulnerability by trying to connect to the device with a non-AnyConnect client. A successful exploit could allow the attacker to exhaust the IP addresses from the assigned local pool, which prevents users from logging in and leads to a denial of service (DoS) condition.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.7 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H.
EPSS exploit prediction
EPSS: 0.011 (64.3th percentile), scored .
Low probability of exploitation in the next 30 days, but still tracked. 64th percentile — 64.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.011 · newest: 0.011 · change: 0.000
Affected products
- Cisco iOS
- Cisco iOS — versions 15.3\(3\)jf11, 15.4(3)sn1a, 15.5\(3\)s1a
- Cisco iOS Xe — versions 3.8.0e, 3.8.1e, 3.8.2e
Weakness classification (CWE)
References
- tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ikev2-eb… (vendor-advisory, Patch, Vendor Advisory)
Frequently asked questions
- What is CVE-2021-1620?
- CVE-2021-1620 is a high-severity vulnerability in Cisco iOS, classified under CWE-563. CVSS score: 7.7/10. Published 2021-09-23.
- How severe is CVE-2021-1620?
- High severity. CVSS v3 base score is 7.7 out of 10.