Secure Client (AnyConnect)
CVE-2023-20240: Multiple in Cisco Secure Client
Multiple vulnerabilities in Cisco Secure Client Software, formerly AnyConnect Secure Mobility Client, could allow an authenticated, local attacker to cause a denial of service (DoS) condition on an affected system.
Published
Automatic summary from the vendor's CVE record. We haven't written a full analysis of this vulnerability yet.
Affected and fixed versions
| Product / branch | Fixed in |
|---|---|
| Cisco Secure Client 4.9 | See the advisory |
| Cisco Secure Client 4.9 | See the advisory |
| Cisco Secure Client 4.9 | See the advisory |
| Cisco Secure Client 4.9 | See the advisory |
| Cisco Secure Client 4.9 | See the advisory |
| Cisco Secure Client 4.9 | See the advisory |
| Cisco Secure Client 4.9 | See the advisory |
| Cisco Secure Client 4.9 | See the advisory |
| Cisco Secure Client 4.9 | See the advisory |
| Cisco Secure Client 4.10 | See the advisory |
| Cisco Secure Client 4.10 | See the advisory |
| Cisco Secure Client 4.10 | See the advisory |
| Cisco Secure Client 4.10 | See the advisory |
| Cisco Secure Client 4.10 | See the advisory |
| Cisco Secure Client 4.10 | See the advisory |
| Cisco Secure Client 4.10 | See the advisory |
| Cisco Secure Client 4.10 | See the advisory |
| Cisco Secure Client 4.10 | See the advisory |
| Cisco Secure Client 4.10 | See the advisory |
| Cisco Secure Client 4.10 | See the advisory |
| Cisco Secure Client 4.10 | See the advisory |
| Cisco Secure Client 4.10 | See the advisory |
| Cisco Secure Client 4.10 | See the advisory |
| Cisco Secure Client 5.0 | See the advisory |
| Cisco Secure Client 5.0 | See the advisory |
| Cisco Secure Client 5.0 | See the advisory |
| Cisco Secure Client 5.0 | See the advisory |
| Cisco Secure Client 5.0 | See the advisory |
| Cisco Secure Client 5.0 | See the advisory |
| Cisco Secure Client 5.0 | See the advisory |
Always confirm against the vendor advisory, which lists every fixed hotfix.
What it is
Multiple vulnerabilities in Cisco Secure Client Software, formerly AnyConnect Secure Mobility Client, could allow an authenticated, local attacker to cause a denial of service (DoS) condition on an affected system. These vulnerabilities are due to an out-of-bounds memory read from Cisco Secure Client Software. An attacker could exploit these vulnerabilities by logging in to an affected device at the same time that another user is accessing Cisco Secure Client on the same system, and then sending crafted packets to a port on that local host. A successful exploit could allow the attacker to crash the VPN Agent service, causing it to be unavailable to all users of the system. To exploit these vulnerabilities, the attacker must have valid credentials on a multi-user system.
Exploitation
The Cisco PSIRT is not aware of any public announcements or malicious use of the vulnerabilities that are described in this advisory.
Sources
KEV status, EPSS score and vendor data refreshed automatically, last on 11 Oct 2026.