How severe is CVE-2020-3367?

CVE-2020-3367 has a CVSS 3.x base score of 7.8, rated high severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2020-3367 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (55th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2020-3367?

CVE-2020-3367 affects Cisco Asyncos. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2020-3367?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2020-3367 published?

CVE-2020-3367 was published on 2020-11-18 and last updated on 2026-06-17.

CVE-2020-3367

CVE-2020-3367 is a high-severity vulnerability in Cisco Asyncos with a CVSS 3.x base score of 7.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-78.

Key facts

Severity: High (CVSS 3.x base score 7.8)
CVSS v2: 7.2
EPSS exploit prediction: 1% (55th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-78
Affected product: Cisco Asyncos
Published: 2020-11-18
Last modified: 2026-06-17

Description

A vulnerability in the log subscription subsystem of Cisco AsyncOS for the Cisco Secure Web Appliance (formerly Web Security Appliance) could allow an authenticated, local attacker to perform command injection and elevate privileges to root. This vulnerability is due to insufficient validation of user-supplied input for the web interface and CLI. An attacker could exploit this vulnerability by authenticating to the affected device and injecting scripting commands in the scope of the log subscription subsystem. A successful exploit could allow the attacker to execute arbitrary commands on the underlying operating system and elevate privileges to root.

Frequently asked questions

What is CVE-2020-3367?: A vulnerability in the log subscription subsystem of Cisco AsyncOS for the Cisco Secure Web Appliance (formerly Web Security Appliance) could allow an authenticated, local attacker to perform command injection and elevate privileges to root. This vulnerability is due to insufficient validation of user-supplied input for the web interface and CLI. An attacker could exploit this vulnerability by authenticating to the affected device and injecting scripting commands in the scope of the log subscription subsystem. A successful exploit could allow the attacker to execute arbitrary commands on the underlying operating system and elevate privileges to root.
How severe is CVE-2020-3367?: CVE-2020-3367 has a CVSS 3.x base score of 7.8, rated high severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2020-3367 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (55th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2020-3367?: CVE-2020-3367 affects Cisco Asyncos. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2020-3367?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2020-3367 published?: CVE-2020-3367 was published on 2020-11-18 and last updated on 2026-06-17.

References

https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-wsa-prv-esc-nPzWZrQj

Affected products (1)

cpe:2.3:o:cisco:asyncos:*:*:*:*:*:*:*:*

More vulnerabilities in Cisco Asyncos

CVE-2025-20393 — Critical (CVSS 10.0): A vulnerability in the Spam Quarantine feature of Cisco AsyncOS Software for Cisco Secure Email Gateway and Cisco…
CVE-2026-76461 — Critical (CVSS 9.8): A vulnerability in the email parsing of Cisco AsyncOS Software for Cisco Secure Email Gateway could allow an…
CVE-2024-20435 — High (CVSS 8.8): A vulnerability in the CLI of Cisco AsyncOS for Secure Web Appliance could allow an authenticated, local attacker to…
CVE-2019-15956 — High (CVSS 8.8): A vulnerability in the web management interface of Cisco AsyncOS Software for Cisco Web Security Appliance (WSA) could…
CVE-2021-34698 — High (CVSS 8.6): A vulnerability in the proxy service of Cisco AsyncOS for Cisco Web Security Appliance (WSA) could allow an…
CVE-2019-1947 — High (CVSS 8.6): A vulnerability in the email message filtering feature of Cisco AsyncOS Software for Cisco Email Security Appliance…

All CVEs affecting Cisco Asyncos →

Other CWE-78 (OS Command Injection) vulnerabilities

CVE-2026-100382 — Critical (CVSS 10.0): Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection') vulnerability in Wikimedia…
CVE-2026-77521 — Critical (CVSS 10.0): MaxKB is an open-source AI assistant for enterprise. Prior to version 2.10.5-lts, assistants with a tool, MCP tool,…
CVE-2026-82004 — Critical (CVSS 10.0): Adobe Campaign Classic (ACC) is affected by an Improper Neutralization of Special Elements used in an OS Command ('OS…
CVE-2026-76197 — Critical (CVSS 10.0): Adobe Campaign Classic (ACC) is affected by an Improper Neutralization of Special Elements used in an OS Command ('OS…
CVE-2026-76195 — Critical (CVSS 10.0): Adobe Campaign Classic (ACC) is affected by an Improper Neutralization of Special Elements used in an OS Command ('OS…
CVE-2026-19188 — Critical (CVSS 10.0): A critical OS command injection vulnerability has been identified in the Haiwell IoT Cloud HMI Gateway product. The…

Browse all CWE-78 (OS Command Injection) vulnerabilities →