CVE-2018-5241
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 · uneditedSymantec Advanced Secure Gateway (ASG) 6.6 and 6.7, and ProxySG 6.5, 6.6, and 6.7 are susceptible to a SAML authentication bypass vulnerability. The products can be configured with a SAML authentication realm to authenticate network users in intercepted proxy traffic. When parsing SAML responses, ASG and ProxySG incorrectly handle XML nodes with comments. A remote attacker can modify a valid SAML response without invalidating its cryptographic signature. This may allow the attacker to bypass user authentication security controls in ASG and ProxySG. This vulnerability only affects authentication of network users in intercepted traffic. It does not affect administrator user authentication for the ASG and ProxySG management consoles.
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 confidenceThe vulnerability exists in SAML response parsing on ASG and ProxySG products where XML comment nodes are incorrectly handled during signature verification. An attacker can inject or modify XML comments within a signed SAML response without invalidating the cryptographic signature, allowing authentication bypass for network users accessing intercepted proxy traffic.
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= 6.6= 6.7= 6.5= 6.6= 6.7CVSS 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
- High
- Availability
- High
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
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.
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Identify the installed productDetermine if the device is running Broadcom Advanced Secure Gateway (ASG) or Broadcom Symantec ProxySG. This is typically visible in the product UI, administrative console, or system information page.Affected if The product is ASG version 6.6 or 6.7, or ProxySG version 6.5, 6.6, or 6.7
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Check the product versionLocate the installed software version in the product administrative interface or via CLI command such as 'show version' or 'version' depending on the platform. Compare this version number against the affected ranges: ASG 6.6, 6.7 and ProxySG 6.5, 6.6, 6.7.Affected if The installed version exactly matches 6.6 or 6.7 for ASG, or 6.5, 6.6, or 6.7 for ProxySG
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Verify SAML authentication is configuredCheck whether SAML (Security Assertion Markup Language) single sign-on is enabled on the device. This is typically found in the proxy configuration, authentication settings, or SSO policy sections of the ASG or ProxySG administrative console.Affected if SAML authentication is actively configured and in use for proxy authentication
You are affected if your device runs an affected ASG or ProxySG version AND SAML authentication is enabled, as the vulnerability lies in SAML response signature verification.
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 vendor patches for ASG 6.6/6.7 and ProxySG 6.5/6.6/6.7. If patches are unavailable, consider compensating controls such as restricting SAML IdP trust to specific entities or implementing additional authentication layers for sensitive access.
- Consultation4.0 h
- Implementation6.0 h
- Testing8.0 h
- Review / QA4.0 h
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Free · runs locallyCheck whether your project pulls in CVE-2018-5241 — 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-2018-5241 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
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- Version or environment caveats, and links to real fixes
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