Email Security ApplianceApplication · Cisco
CVE-2020-3137
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedA vulnerability in the web-based management interface of Cisco Email Security Appliance (ESA) could allow an unauthenticated, remote attacker to conduct a cross-site scripting (XSS) attack against a user of the web-based management interface of an affected device. The vulnerability exists because the web-based management interface of the affected device does not properly validate user-supplied input. An attacker could exploit this vulnerability by persuading a user to click a malicious link. A successful exploit could allow the attacker to execute arbitrary script code in the context of the affected interface or to access sensitive, browser-based information.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · high confidenceA cross-site scripting (XSS) vulnerability exists in the web-based management interface of Cisco Email Security Appliance (ESA). The interface fails to properly validate user-supplied input, allowing an unauthenticated remote attacker to inject malicious scripts via a crafted link. Successful exploitation enables arbitrary script execution in the context of the affected interface or access to sensitive browser-based information.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data
Email Security ApplianceApplication
<= 13.0.0CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- None
- User interaction
- Required
- Scope
- Changed
- Confidentiality
- Low
- Integrity
- Low
- Availability
- None
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
-
Identify the Cisco Email Security ApplianceLocate the device or software and confirm it is specifically a Cisco Email Security Appliance (ESA). This vulnerability does not apply to other Cisco products.Affected if The device is not a Cisco ESA product.
-
Determine the installed ESA versionAccess the ESA web-based management interface and navigate to the About page or use the 'version' command in the CLI to display the installed software version.Affected if The installed version is 13.0.0 or any earlier version (versions prior to the fixed release).
-
Verify the web-based management interface is enabledCheck if the ESA web-based management interface (HTTP/HTTPS) is configured and active. This can be done via the CLI command 'interfaceconfig' or through the web interface under Network > IP Interfaces.Affected if The web management interface is enabled and accessible.
-
Assess network accessibility of the management interfaceDetermine if the ESA web management interface is exposed to untrusted networks or the internet. Review firewall rules and interface bindings to confirm whether the interface is reachable from outside the trusted network.Affected if The web management interface is reachable by unauthenticated remote attackers from untrusted networks.
A user is affected if they have a Cisco Email Security Appliance running version 13.0.0 or earlier with the web-based management interface enabled and accessible, as the XSS vulnerability can be exploited by an unauthenticated remote attacker via a crafted link.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
From vendor dataApply the vendor patch or workarounds provided by Cisco for this vulnerability. Additionally, implement user awareness training to reduce the likelihood of users clicking malicious links, though patching is the primary remediation.
Fix this in Email Security Appliance
Scoped from the published advisory
- Consultation4.0 h
- Implementation4.0 h
- Testing4.0 h
- Review / QA2.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,968.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2020-3137 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2020-3137 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.
A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.
- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
- No spam, self-promotion, credentials, or personal data