CVE-2017-6638

CVE-2017-6638 is a high-severity vulnerability in Cisco Anyconnect Secure Mobility Client with a CVSS 3.x base score of 7.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-20.

Key facts

Description

A vulnerability in how DLL files are loaded with Cisco AnyConnect Secure Mobility Client for Windows could allow an authenticated, local attacker to install and run an executable file with privileges equivalent to the Microsoft Windows SYSTEM account. The vulnerability is due to incomplete input validation of path and file names of a DLL file before it is loaded. An attacker could exploit this vulnerability by creating a malicious DLL file and installing it in a specific system directory. A successful exploit could allow the attacker to execute commands on the underlying Microsoft Windows host with privileges equivalent to the SYSTEM account. The attacker would need valid user credentials to exploit this vulnerability. This vulnerability affects all Cisco AnyConnect Secure Mobility Client for Windows software versions prior to 4.4.02034. Cisco Bug IDs: CSCvc97928.

Frequently asked questions

What is CVE-2017-6638?
A vulnerability in how DLL files are loaded with Cisco AnyConnect Secure Mobility Client for Windows could allow an authenticated, local attacker to install and run an executable file with privileges equivalent to the Microsoft Windows SYSTEM account. The vulnerability is due to incomplete input validation of path and file names of a DLL file before it is loaded. An attacker could exploit this vulnerability by creating a malicious DLL file and installing it in a specific system directory. A successful exploit could allow the attacker to execute commands on the underlying Microsoft Windows host with privileges equivalent to the SYSTEM account. The attacker would need valid user credentials to exploit this vulnerability. This vulnerability affects all Cisco AnyConnect Secure Mobility Client for Windows software versions prior to 4.4.02034. Cisco Bug IDs: CSCvc97928.
How severe is CVE-2017-6638?
CVE-2017-6638 has a CVSS 3.x base score of 7.8, rated high severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2017-6638 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (29th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2017-6638?
CVE-2017-6638 affects Cisco Anyconnect Secure Mobility Client. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2017-6638?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2017-6638 published?
CVE-2017-6638 was published on 2017-06-08 and last updated on 2026-06-17.

References

Affected products (1)

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