CVE-2020-3187

CVE-2020-3187 is a critical-severity vulnerability in Cisco Secure Firewall Threat Defense with a CVSS 3.x base score of 9.1. Its EPSS exploit-prediction score of 97% places it in the 100th percentile, indicating an elevated likelihood of exploitation. The underlying weakness is classified as CWE-22.

Key facts

Description

A vulnerability in the web services interface of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to conduct directory traversal attacks and obtain read and delete access to sensitive files on a targeted system. The vulnerability is due to a lack of proper input validation of the HTTP URL. An attacker could exploit this vulnerability by sending a crafted HTTP request containing directory traversal character sequences. An exploit could allow the attacker to view or delete arbitrary files on the targeted system. When the device is reloaded after exploitation of this vulnerability, any files that were deleted are restored. The attacker can only view and delete files within the web services file system. This file system is enabled when the affected device is configured with either WebVPN or AnyConnect features. This vulnerability can not be used to obtain access to ASA or FTD system files or underlying operating system (OS) files. Reloading the affected device will restore all files within the web services file system.

Frequently asked questions

What is CVE-2020-3187?
A vulnerability in the web services interface of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to conduct directory traversal attacks and obtain read and delete access to sensitive files on a targeted system. The vulnerability is due to a lack of proper input validation of the HTTP URL. An attacker could exploit this vulnerability by sending a crafted HTTP request containing directory traversal character sequences. An exploit could allow the attacker to view or delete arbitrary files on the targeted system. When the device is reloaded after exploitation of this vulnerability, any files that were deleted are restored. The attacker can only view and delete files within the web services file system. This file system is enabled when the affected device is configured with either WebVPN or AnyConnect features. This vulnerability can not be used to obtain access to ASA or FTD system files or underlying operating system (OS) files. Reloading the affected device will restore all files within the web services file system.
How severe is CVE-2020-3187?
CVE-2020-3187 has a CVSS 3.x base score of 9.1, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability none.
Is CVE-2020-3187 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 97% (100th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2020-3187?
CVE-2020-3187 primarily affects Cisco Secure Firewall Threat Defense. In total, 14 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2020-3187?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2020-3187 published?
CVE-2020-3187 was published on 2020-05-06 and last updated on 2026-08-11.

References

Affected products (14)

More vulnerabilities in Cisco Secure Firewall Threat Defense

All CVEs affecting Cisco Secure Firewall Threat Defense →

Other CWE-22 (Path Traversal) vulnerabilities

Browse all CWE-22 (Path Traversal) vulnerabilities →