CVE-2018-5241

CVE-2018-5241 is a critical-severity vulnerability in Broadcom Advanced Secure Gateway with a CVSS 3.x base score of 9.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low.

Key facts

Description

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.

Frequently asked questions

What is CVE-2018-5241?
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.
How severe is CVE-2018-5241?
CVE-2018-5241 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2018-5241 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 5% (91st percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2018-5241?
CVE-2018-5241 primarily affects Broadcom Advanced Secure Gateway. In total, 5 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2018-5241?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2018-5241 published?
CVE-2018-5241 was published on 2018-05-29 and last updated on 2026-06-17.

References

Affected products (5)

More vulnerabilities in Broadcom Advanced Secure Gateway

All CVEs affecting Broadcom Advanced Secure Gateway →