Improper input validation in Cisco Anyconnect Secure Mobility Client

CVE-2020-3556

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.

Vulnerability class: Drupalgeddon 2 (CVE-2018-7600)

EPSS: 0.004 (37.5th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 7.3 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H.

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2020-3556?
CVE-2020-3556 is a high-severity vulnerability in Cisco Anyconnect Secure Mobility Client, classified under Improper Input Validation. CVSS score: 7.3/10. Published 2020-11-06.
How severe is CVE-2020-3556?
High severity. CVSS v3 base score is 7.3 out of 10.
Is CVE-2020-3556 known to be exploited?
1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.