SB2021050620 - Multiple vulnerabilities in Cisco AnyConnect Secure Mobility Client

Description

This security bulletin contains information about 3 vulnerabilities.

1) Creation of Temporary File With Insecure Permissions (CVE-ID: CVE-2021-1426)

CWE-ID: CWE-378 - Creation of Temporary File With Insecure Permissions

CVSSv4: CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear

The vulnerability allows a local user to perform an executable hijacking attack.

The vulnerability exists due to a temporary file with insecure permissions is created during the uninstall process. A local user can overwrite the temporary file before it is accessed for execution and execute arbitrary code on the target device.

2) Insecure DLL loading (CVE-ID: CVE-2021-1427)

CWE-ID: CWE-427 - Uncontrolled Search Path Element

CVSSv4: CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear

The vulnerability allows a local user to compromise vulnerable system.

The vulnerability exists due to the application loads a DLL file from a user-writable directory. A local user can place a specially crafted .dll file and execute arbitrary code on victim's system.

3) Insecure DLL loading (CVE-ID: CVE-2021-1430)

CWE-ID: CWE-427 - Uncontrolled Search Path Element

CVSSv4: CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear

The vulnerability allows a local user to compromise vulnerable system.

The vulnerability exists due to a temporary file with insecure permissions is created during the upgrade process. A local user can place a specially crafted .dll file and execute arbitrary code on victim's system.

Remediation

Install update from vendor's website.

References

• https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-anyconnect-code-exec-jR3tWTA6