CVE-2018-5506

CVE-2018-5506 is a critical-severity vulnerability in F5 Big-ip Local Traffic Manager 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

In F5 BIG-IP 13.0.0, 12.1.0-12.1.2, 11.6.1, 11.5.1-11.5.5, or 11.2.1 the Apache modules apache_auth_token_mod and mod_auth_f5_auth_token.cpp allow possible unauthenticated bruteforce on the em_server_ip authorization parameter to obtain which SSL client certificates used for mutual authentication between BIG-IQ or Enterprise Manager (EM) and managed BIG-IP devices.

Frequently asked questions

What is CVE-2018-5506?
In F5 BIG-IP 13.0.0, 12.1.0-12.1.2, 11.6.1, 11.5.1-11.5.5, or 11.2.1 the Apache modules apache_auth_token_mod and mod_auth_f5_auth_token.cpp allow possible unauthenticated bruteforce on the em_server_ip authorization parameter to obtain which SSL client certificates used for mutual authentication between BIG-IQ or Enterprise Manager (EM) and managed BIG-IP devices.
How severe is CVE-2018-5506?
CVE-2018-5506 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-2018-5506 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (50th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2018-5506?
CVE-2018-5506 primarily affects F5 Big-ip Local Traffic Manager. In total, 52 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2018-5506?
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-2018-5506 published?
CVE-2018-5506 was published on 2018-04-13 and last updated on 2026-06-17.

References

Affected products (52)

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