Sterling External Authentication ServerApplication · Ibm

CVE-2020-4462

HIGH · 8.2 CVSS v3.1 Published 2020-07-16
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
91/100
Remediation priority · Urgent
Remotely reachable No privileges Zero-click

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 · unedited
IBM Sterling External Authentication Server 6.0.1, 6.0.0, 2.4.3.2, and 2.4.2 and IBM Sterling Secure Proxy 6.0.1, 6.0.0, 3.4.3, and 3.4.2 are vulnerable to an XML External Entity Injection (XXE) attack when processing XML data. A remote attacker could exploit this vulnerability to expose sensitive information or consume memory resources. IBM X-Force ID: 181482.

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 confidence

IBM Sterling External Authentication Server and Sterling Secure Proxy contain an XML External Entity Injection (XXE) vulnerability when processing XML data. A remote unauthenticated attacker can exploit this to read sensitive files from the server filesystem or cause memory exhaustion through malicious XML payloads containing external entity references.

MitigationDisable external entity processing in all XML parsers within the affected products, implement strict input validation for XML submissions, and consider deploying XML firewalls or API gateways to filter malicious XML requests.

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
Sterling External Authentication ServerApplication
Affected:= 2.4.2.0= 2.4.3.2= 6.0.0.0= 6.0.1.0
Sterling Secure ProxyApplication
Affected:= 3.4.2.0= 3.4.3.0= 6.0.0.0= 6.0.1.0

CVSS 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
None
Scope
Unchanged
Confidentiality
High
Integrity
None
Availability
Low

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:L

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 checks

Work through these to decide whether this CVE applies to you.

  1. Identify installed IBM Sterling product
    Check for running processes or installed software for 'Sterling External Authentication Server' or 'Sterling Secure Proxy'. Look in installation directories (commonly under /opt/ibm or C:\Program Files\IBM) or list running Windows services containing 'Sterling' in the name.
    Affected if Either IBM Sterling External Authentication Server or Sterling Secure Proxy is installed
  2. Determine installed version
    Locate version information in the product's About or version file. For Sterling External Authentication Server, check <install_dir>/version.txt or the administration console. For Sterling Secure Proxy, check <install_dir>/config/version.properties or the management console.
    Affected if Installed version matches 2.4.2.0, 2.4.3.2, 6.0.0.0, 6.0.1.0 (Sterling External Authentication Server) or 3.4.2.0, 3.4.3.0, 6.0.0.0, 6.0.1.0 (Sterling Secure Proxy)
  3. Verify XML processing is active
    Confirm the product is configured to accept or process XML-based requests. Check configuration files in the config directory for XML parser settings, particularly looking for 'XML', 'parser', or 'DOCTYPE' related configurations.
    Affected if XML processing feature is enabled and the product accepts XML input from external sources
  4. Check network exposure of XML endpoints
    Identify listening network ports and services exposed by the product. Review firewall rules and access controls around the Sterling product installations. Common ports include 8443, 8444, or custom ports configured during installation.
    Affected if The XML processing interface is accessible from network (untrusted sources) without authentication

You are affected if you run any of the listed versions of IBM Sterling External Authentication Server or Sterling Secure Proxy and the XML processing interface is network-accessible.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

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 data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Disable external entity processing in all XML parsers within the affected products, implement strict input validation for XML submissions, and consider deploying XML firewalls or API gateways to filter malicious XML requests.

Fix this in Sterling External Authentication Server Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing6.0 h
  • Review / QA3.0 h
21.0 hours of engineering $3,680
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2020-4462 in production — separate from our analysis above.

No notes yet

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What this is

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.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
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