CVE-2026-20152
Authentication Bypass in Cisco AsyncOS via Improper Input Validation
Publication date: 2026-04-15
Last updated on: 2026-04-15
Assigner: Cisco Systems, Inc.
Description
Description
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| cisco | asyncos | to 15.2 (exc) |
| cisco | secure_web_appliance | * |
| cisco | asyncos | * |
Helpful Resources
Exploitability
| CWE ID | Description |
|---|---|
| CWE-305 | The authentication algorithm is sound, but the implemented mechanism can be bypassed as the result of a separate weakness that is primary to the authentication error. |
Attack-Flow Graph
AI Powered Q&A
Can you explain this vulnerability to me?
This vulnerability exists in the authentication service feature of Cisco AsyncOS Software for Cisco Secure Web Appliance. It allows an unauthenticated, remote attacker to bypass authentication policy requirements by exploiting improper validation of user-supplied authentication input in HTTP requests.
An attacker can send specially crafted HTTP requests containing specific authentication requests to the affected device. If successful, the attacker can bypass the device's policy enforcement.
How does this vulnerability affect compliance with common standards and regulations (like GDPR, HIPAA)?:
This vulnerability allows an unauthenticated, remote attacker to bypass authentication policy requirements on Cisco Secure Web Appliance devices, potentially enabling restricted HTTP requests to pass through the appliance.
While there is no direct impact on the device itself beyond the authentication bypass, the ability to circumvent policy enforcement could lead to unauthorized access or actions that may affect the integrity of protected data or systems.
Such unauthorized access or policy bypass could have implications for compliance with standards and regulations like GDPR or HIPAA, which require strict access controls and protection of sensitive data.
However, the provided information does not explicitly detail the compliance impact or any direct linkage to these regulations.
How can this vulnerability be detected on my network or system? Can you suggest some commands?
There is no specific information provided about detection methods or commands to identify this vulnerability on your network or system.
What immediate steps should I take to mitigate this vulnerability?
Cisco strongly recommends upgrading to fixed software releases to remediate this issue.
- Upgrade Cisco AsyncOS to version 15.2.5-013 or later.
- Ensure device compatibility and memory requirements before upgrading.
- Obtain fixed software through authorized channels or Cisco TAC if necessary.
How can this vulnerability impact me? :
Exploiting this vulnerability could allow an attacker to bypass authentication policies and send HTTP requests that should be restricted by the Cisco Secure Web Appliance.
While there is no direct impact to the device itself, the attacker could potentially access or send unauthorized HTTP requests that the device is supposed to block.