CVE-2020-3556
Cisco AnyConnect Secure Mobility Client Arbitrary Code Execution Vulnerability
A vulnerability in the interprocess communication (IPC) channel of Cisco AnyConnect Secure Mobility Client Software could allow an authenticated, local attacker to cause a targeted AnyConnect user to execute a malicious script. The vulnerability is due to a lack of authentication to the IPC listener. An attacker could exploit this vulnerability by sending crafted IPC messages to the AnyConnect client IPC listener. A successful exploit could allow an attacker to cause the targeted AnyConnect user to execute a script. This script would execute with the privileges of the targeted AnyConnect user. In order to successfully exploit this vulnerability, there must be an ongoing AnyConnect session by the targeted user at the time of the attack. To exploit this vulnerability, the attacker would also need valid user credentials on the system upon which the AnyConnect client is being run. Cisco has not released software updates that address this vulnerability.
Attack profile
How easy it is to exploit
- Attack vector
- Local
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- Required
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
7.3
Cisco AnyConnect Secure Mobility Client Arbitrary Code Execution Vulnerability
A vulnerability in the interprocess communication (IPC) channel of Cisco AnyConnect Secure Mobility Client Software could allow an authenticated, local attacker to cause a targeted AnyConnect user to execute a malicious script. The vulnerability is due to a lack of authentication to the IPC listener. An attacker could exploit this vulnerability by sending crafted IPC messages to the AnyConnect client IPC listener. A successful exploit could allow an attacker to cause the targeted AnyConnect user to execute a script. This script would execute with the privileges of the targeted AnyConnect user. In order to successfully exploit this vulnerability, there must be an ongoing AnyConnect session by the targeted user at the time of the attack. To exploit this vulnerability, the attacker would also need valid user credentials on the system upon which the AnyConnect client is being run. Cisco has not released software updates that address this vulnerability.
- Record
CVE-2020-3556- CVSS 3.1
- 7.3 High
CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H - Weakness
- CWE-20
- Updated
- 2026-11-02
EUVDEUVD-2020-24827
7.3
A vulnerability in the interprocess communication (IPC) channel of Cisco AnyConnect Secure Mobility Client Software could allow an authenticated, local attacker to cause a targeted AnyConnect user to execute a malicious script. The vulnerability is due to a lack of authentication to the IPC listener. An attacker could exploit this vulnerability by sending crafted IPC messages to the AnyConnect client IPC listener. A successful exploit could allow an attacker to cause the targeted AnyConnect user to execute a script. This script would execute with the privileges of the targeted AnyConnect user. In order to successfully exploit this vulnerability, there must be an ongoing AnyConnect session by the targeted user at the time of the attack. To exploit this vulnerability, the attacker would also need valid user credentials on the system upon which the AnyConnect client is being run. Cisco has not released software updates that address this vulnerability.
- Record
EUVD-2020-24827- CVSS 3.1
- 7.3 High
CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H - Updated
- 2026-11-03
GitHub AdvisoriesGHSA-v6p8-gw74-vfg4 No score
A vulnerability in the interprocess communication (IPC) channel of Cisco AnyConnect Secure...
A vulnerability in the interprocess communication (IPC) channel of Cisco AnyConnect Secure Mobility Client Software could allow an authenticated, local attacker to cause a targeted AnyConnect user to execute a malicious script. The vulnerability is due to a lack of authentication to the IPC listener. An attacker could exploit this vulnerability by sending crafted IPC messages to the AnyConnect client IPC listener. A successful exploit could allow an attacker to cause the targeted AnyConnect user to execute a script. This script would execute with the privileges of the targeted AnyConnect user. In order to successfully exploit this vulnerability, there must be an ongoing AnyConnect session by the targeted user at the time of the attack. To exploit this vulnerability, the attacker would also need valid user credentials on the system upon which the AnyConnect client is being run. Cisco has not released software updates that address this vulnerability.
- Record
GHSA-v6p8-gw74-vfg4- Updated
- 2026-11-02
NVD
7.3
A vulnerability in the interprocess communication (IPC) channel of Cisco AnyConnect Secure Mobility Client Software could allow an authenticated, local attacker to cause a targeted AnyConnect user to execute a malicious script. The vulnerability is due to a lack of authentication to the IPC listener. An attacker could exploit this vulnerability by sending crafted IPC messages to the AnyConnect client IPC listener. A successful exploit could allow an attacker to cause the targeted AnyConnect user to execute a script. This script would execute with the privileges of the targeted AnyConnect user. In order to successfully exploit this vulnerability, there must be an ongoing AnyConnect session by the targeted user at the time of the attack. To exploit this vulnerability, the attacker would also need valid user credentials on the system upon which the AnyConnect client is being run. Cisco has not released software updates that address this vulnerability.
- Record
CVE-2020-3556- CVSS 3.1
- 7.3 High
CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H - CVSS 2.0
- 4.4 Medium
AV:L/AC:M/Au:N/C:P/I:P/A:P - Weakness
- CWE-20
- Updated
- 2026-11-02
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases, published | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2020-3556 is a high vulnerability (CVSS 7.3) in Cisco Anyconnect Secure Mobility Client, published November 6, 2020. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.45%, the 39th percentile. No source names a fixed version.