Symantec 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.
CVE-2018-5241
CRITICALNVD 9.89.8—
EchelonGraph scoreMEDIUM confidence
Score 9.8 from GitHub Security Advisory (severity: CRITICAL) published 2022-05-13. NVD baseline CVSS 9.8; sources differ by 0.0.
Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
9.8
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
- High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 5%CVSS: 9.8Exploit: NoneExposed: 0
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
- CVSS v3
- 9.8
- EG Score
- 9.8(medium)
- EPSS
- 90.9%
- KEV
- Not listed
Published
May 29, 2018
Last Modified
November 21, 2024
Advisory Details (2)
Auto-updated May 25, 2026No patch confirmed yet.
Data Freshness Timeline
(refreshed 12× in last 7d / 42× in last 30d)
Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.
- 2026-07-07 13:42 UTCEPSS rescore
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- 2026-06-21 14:54 UTCEPSS rescore
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- 2026-05-29 13:41 UTCEPSS rescore
- 2026-05-28 13:43 UTCEPSS rescore
- 2026-05-28 13:42 UTCEPSS rescore
- 2026-05-28 07:46 UTCEG score recompute
- 2026-05-28 07:46 UTCGHSA enrichment
- 2026-05-27 13:38 UTCEPSS rescore
- 2026-05-26 13:42 UTCEPSS rescore
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- 2026-05-26 07:17 UTCEPSS rescore
- 2026-05-26 07:17 UTCEPSS rescore
Frequently asked(5)
What is CVE-2018-5241?
CVE-2018-5241 is a critical vulnerability published on May 29, 2018. Symantec 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,…
When was CVE-2018-5241 disclosed?
CVE-2018-5241 was first published in the National Vulnerability Database on May 29, 2018, with the most recent update on November 21, 2024. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2018-5241 actively exploited?
CVE-2018-5241 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 90.9% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2018-5241?
CVE-2018-5241 has a CVSS v3 base score of 9.8 (NVD).
How do I remediate CVE-2018-5241?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2018-5241, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.
Dependency Blast Radius
Explore the affected products and dependency analysis for CVE-2018-5241
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