CVE-2020-3368Network attack vector

URL reputation bypass via insufficient URL validation

Published Jun 18, 2020 · Updated Nov 15, 2024

URL filter bypass in Cisco AsyncOS for Secure Email Gateway before 13.5.0 allows remote attackers to pass malicious URLs through. The antispam URL-reputation path insufficiently validates specially crafted URLs, causing configured reputation checks to be skipped. No credentials or user interaction are required; the bounded result is delivery of malicious URLs that the configured filters would otherwise block.

CVSS severity5.8
Medium
EPSS probability1.38%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

URL filter bypass in Cisco AsyncOS for Secure Email Gateway before 13.5.0 allows remote attackers to pass malicious URLs through. The antispam URL-reputation path insufficiently validates specially crafted URLs, causing configured reputation checks to be skipped. No credentials or user interaction are required; the bounded result is delivery of malicious URLs that the configured filters would otherwise block.

The record

CVE
CVE-2020-3368
Published
Jun 18, 2020
Updated
Nov 15, 2024
Vendor
ClamAV
Product
Cisco Secure Email Gateway
Classifications
CWE-20
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 18, 2020CVE publishedPublication date reported by the CVE source.
  2. Nov 15, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=n/a

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

ClamAV · Cisco Secure Email Gatewayversion=n/a

Published CVSS scores

5.0NIST NVDAV:N/AC:L/Au:N/C:N/I:P/A:N
5.8Cisco Systems, Inc.CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N/E:X/RL:X/RC:X
5.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-20Improper Input Validation

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo