CVE-2022-20805
lowpriority · track · 16OT risk · elevatedEPSS 0.002 · 8 %ileEURUUSEPSS · scored 2026-10-27
A vulnerability in the automatic decryption process in Cisco Umbrella Secure Web Gateway (SWG) could allow an authenticated, adjacent attacker to bypass the SSL decryption and content filtering policies on an affected system. This vulnerability is due to how the decryption function uses the TLS Sever Name Indication (SNI) extension of an HTTP request to discover the destination domain and determine if the request needs to be decrypted. An attacker could exploit this vulnerability by sending a crafted request over TLS from a client to an unknown or controlled URL. A successful exploit could allow an attacker to bypass the decryption process of Cisco Umbrella SWG and allow malicious content to be downloaded to a host on a protected network. There are workarounds that address this vulnerability.
remediations
Vendor fix, mitigation, or workaround guidance, as published by each source.
A vendor fix is available.
- FixedCisco Umbrella Insights Virtual Appliancecisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com - WorkaroundCisco Umbrella Insights Virtual Appliancecisco_csaf
As a workaround, use the instructions in the Cisco Umbrella Secure Internet Gateway (SIG) User Guide ["https://docs.umbrella.com/umbrella-user-guide/docs"] to create a rule to block traffic that could bypass the SSL decryption and content filtering policies. Step 1: Follow the instructions in the Add a Web Destination List ["https://docs.umbrella.com/umbrella-user-guide/docs/add-a-web-policy-destination-list"] section to create destination lists to control identity access to websites. Step 2: Follow the instructions in the Add a Ruleset to the Web Policy ["https://docs.umbrella.com/umbrella-user-guide/docs/add-a-rules-based-policy"] to create a ruleset. Step 3: Follow the instructions in the Add Rules to a Ruleset ["https://docs.umbrella.com/umbrella-user-guide/docs/add-rules-to-a-ruleset"] section to create a Block rule. From the Rule Action drop-down list, choose Block. Under Destinations, click Add Destination and then click Destination Lists. From the drop-down menu, choose the destination lists that were created in Step 1. While this workaround has been deployed and was proven successful in a test environment, customers should determine the applicability and effectiveness in their own environment and under their own use conditions. Customers should be aware that any workaround or mitigation that is implemented may negatively impact the functionality or performance of their network based on intrinsic customer deployment scenarios and limitations. Customers should not deploy any workarounds or mitigations before first evaluating the applicability to their own environment and any impact to such environment.
cvss
Technical severity, 0–10. One row per scoring source.
base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · low–medium · 2.7–4.1
ssvc
A stakeholder decision — act, attend, or track — from exploitation and impact.
weaknesses
The CWE weakness classes this flaw belongs to.
affected products (4)
Products and version ranges known to be affected.
- cisco umbrella secure web gatewayall versionsnvdUScpe:2.3:a:cisco:umbrella_secure_web_gateway:*:*:*:*:*:*:*:*
advisories (1)
Vendor and ecosystem advisories describing this.
- cisco-sa-uswg-fdbps-xtTRKpp6Cisco Umbrella Secure Web Gateway File Decryption Bypass Vulnerability2022-04-20csaf · cisco_csafUS
A vulnerability in the automatic decryption process in Cisco Umbrella Secure Web Gateway (SWG) could allow an authenticated, adjacent attacker to bypass the SSL decryption and content filtering policies on an affected system. This vulnerability is due to how the decryption function uses the TLS Sever Name Indication (SNI) extension of an HTTPS request to discover the destination domain and determine if the request needs to be decrypted. An attacker could exploit this vulnerability by sending a crafted request over TLS from a client to an unknown or controlled URL. A successful exploit could allow an attacker to bypass the decryption process of Cisco Umbrella SWG and allow malicious content to be downloaded to a host on a protected network. There are workarounds that address this vulnerability. This advisory is available at the following link: https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-uswg-fdbps-xtTRKpp6 ["https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-uswg-fdbps-xtTRKpp6"]
also known as (5)
Other names and identifiers for this entity.
sources
Which sources assert this record, and when.
references (5)
External citations — patches, advisories, analysis.
- https://cxsecurity.com/cveshow/CVE-2022-20805/cnnvd
- https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-uswg-fdbps-xtTRKpp6cnnvd
- https://www.cybersecurity-help.cz/vdb/SB2022042123cnnvd
- https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-uswg-fdbps-xtTRKpp6enisa_euvd
- https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-uswg-fdbps-xtTRKpp6Vendor Advisorynvd
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