Product:	Impacted Versions:	CVE ID:	Impact of Vulnerabilities:	Severity Ratings:	CVSS v3.1 Base/Temporal Scores:
Web Gateway	Prior to: 10.0.4 9.2.8 8.2.17	CVE-2021-23885	CWE-269: Improper Privilege Management	Critical	9.0 / 8.3
Recommendations:	Install or update to Web Gateway 8.2.17, 9.2.8, or 10.0.4
Security Bulletin Replacement:	None
Location of updated software:	Product Downloads site

Article contents:

• Vulnerability Description
• Remediation
• Frequently Asked Questions (FAQs)
• Resources
• Disclaimer

Vulnerability Description
This exploit requires the attacker to gain authenticated access to the Web Gateway User Interface. We recommend that access to the User Interface is restricted to trusted networks and that the number of people authorized to log on is limited. This issue results in commands being executed as root on the Web Gateway appliance.

We are not aware of this issue being exploited in the field.
 
CVE-2021-23885
Privilege escalation vulnerability in Web Gateway prior to 9.2.8 allows an authenticated user to gain elevated privileges through the User Interface and execute commands on the appliance via incorrect improper neutralization of user input in the troubleshooting page.
https://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2021-23885   
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-23885
 
Remediation
To remediate this issue:

• Customers on the Controlled release branch 10.0.x: Update to 10.0.4.
• Customers on 9.2.x: Update to 9.2.8.
• Customers on 8.2.x:  Upgrade to 9.2.8 or update to 8.2.17.

Go to the Product Downloads site, and download the applicable product update file:
 

Product	Version	Type	Release Date
Web Gateway	10.0.4	Update (Controlled release)	February 15, 2021
Web Gateway	9.2.8	Update	February 15, 2021
Web Gateway	8.2.17	Update	February 15, 2021

 
Download and Installation Instructions
For instructions to download product updates and hotfixes, see: KB56057 - How to download Enterprise product updates and documentation. Review the Release Notes and the Installation Guide for instructions on how to install these updates. All documentation is available on the Product Documentation site.
 
Frequently Asked Questions (FAQs)
How do I know if my product is vulnerable?
For Appliances:
Use the following instructions for Appliance-based products:

1. Open the Administrator's User Interface (UI).
2. Click the About link. The product version displays.

What is CVSS?
CVSS, or Common Vulnerability Scoring System, is the result of the National Infrastructure Advisory Council's effort to standardize a system of assessing the criticality of a vulnerability. This system offers an unbiased criticality score between 0 and 10 that customers can use to judge how critical a vulnerability is and plan accordingly. For more information, visit the CVSS website.
 
When calculating CVSS scores, we've adopted a philosophy that fosters consistency and repeatability. Our guiding principle for CVSS scoring is to score the exploit under consideration by itself. We consider only the immediate and direct impact of the exploit under consideration. We do not factor into a score any potential follow-on exploits that might be made possible by the successful exploitation of the issue being scored.
 
What are the CVSS scoring metrics?

CVE-2021-23885: Privilege escalation vulnerability in Web Gateway
 

Base Score	9.0
Attack Vector (AV)	Network (N)
Attack Complexity (AC)	Low (L)
Privileges Required (PR)	Low (L)
User Interaction (UI)	Required (R)
Scope (S)	Changed (C)
Confidentiality (C)	High (H)
Integrity (I)	High (H)
Availability (A)	High (H)
Temporal Score (Overall)	8.3
Exploitability (E)	Proof of Concept (P)
Remediation Level (RL)	Official Fix (O)
Report Confidence (RC)	Confirmed (C)

 
NOTE: The below CVSS version 3.1 vector was used to generate this score.
https://nvd.nist.gov/vuln-metrics/cvss/v3-calculator?vector=AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:H/E:P/RL:O/RC:C&version=3.1

Where can I find a list of all Security Bulletins?
All Security Bulletins are published on our Knowledge Center. Security Bulletins are retired (removed) once a product is both End of Sale and End of Support (End of Life).
 
How do I report a product vulnerability to you?
If you have information about a security issue or vulnerability with a product, follow the instructions provided in KB95563 - Report a vulnerability.
 
How do you respond to this and any other reported security flaws?
Our key priority is the security of our customers. If a vulnerability is found within any of our software or services, we work closely with the relevant security software development team to ensure the rapid and effective development of a fix and communication plan.
 
We only publish Security Bulletins if they include something actionable such as a workaround, mitigation, version update, or hotfix. Otherwise, we would simply be informing the hacker community that our products are a target, putting our customers at greater risk. For products that are updated automatically, a non-actionable Security Bulletin might be published to acknowledge the discoverer.
 
To view our PSIRT policy, see KB95564 - About PSIRT.

Resources

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Disclaimer
The information provided in this Security Bulletin is provided as is without warranty of any kind. We disclaim all warranties, either express or implied, including the warranties of merchantability and fitness for a particular purpose. In no event shall we or our suppliers be liable for any damages whatsoever including direct, indirect, incidental, consequential, loss of business profits, or special damages, even if we or our suppliers have been advised of the possibility of such damages. Some states don't allow the exclusion or limitation of liability for consequential or incidental damages, so the preceding limitation may not apply.

Any future product release dates mentioned in this Security Bulletin are intended to outline our general product direction, and they shouldn't be relied on in making a purchasing decision. The product release dates are for information purposes only, and may not be incorporated into any contract. The product release dates aren't a commitment, promise, or legal obligation to deliver any material, code, or functionality. The development, release, and timing of any features or functionality described for our products remain at our sole discretion and may be changed or canceled at any time.