SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityModified

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.

CRITICAL 9.8EPSS 4.62%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (4.62%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

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.

CVSS 3.0
9.8 CRITICALCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS
4.62% probability · 91th percentile
CISA KEV
Not listed
Affected
broadcom/advanced secure gateway · broadcom/symantec proxysg
Source
secure@symantec.com

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.