CVE-2019-1886 Explained : Impact and Mitigation

Cisco Web Security Appliance (WSA) contains a vulnerability in its HTTPS decryption function that could lead to a denial of service (DoS) attack. This weakness arises from inadequate SSL server certificate validation.

Understanding CVE-2019-1886

The vulnerability in Cisco Web Security Appliance (WSA) could allow an attacker to induce a DoS situation by exploiting the HTTPS decryption feature.

What is CVE-2019-1886?

The weakness in HTTPS decryption in Cisco WSA allows an unauthorized attacker to trigger a DoS attack by inserting a defective certificate into a web server.

The Impact of CVE-2019-1886

CVSS Base Score: 8.6 (High Severity)
Attack Vector: Network
Availability Impact: High
The vulnerability could lead to an unexpected restart of the proxy process on the affected device.

Technical Details of CVE-2019-1886

The technical aspects of the vulnerability in Cisco Web Security Appliance.

Vulnerability Description

The flaw results from insufficient validation of SSL server certificates.

Affected Systems and Versions

Affected Product: Cisco Web Security Appliance (WSA)
Vendor: Cisco
Affected Versions: Less than 10.5.5-005

Exploitation Mechanism

An attacker can insert a defective certificate into a web server and send a request via the Cisco WSA to induce a DoS situation.

Mitigation and Prevention

Steps to mitigate and prevent the CVE-2019-1886 vulnerability.

Immediate Steps to Take

Apply vendor-provided patches or updates promptly.
Monitor Cisco's security advisories for any further updates.

Long-Term Security Practices

Implement proper SSL certificate validation procedures.
Regularly update and patch security devices and software.

Patching and Updates

Ensure that the Cisco Web Security Appliance is updated to a version that addresses the vulnerability.