CVE-2018-5527

CVE-2018-5527 is a high-severity vulnerability in F5 Big-ip Access Policy Manager with a CVSS 3.x base score of 7.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-772.

Key facts

• Severity: High (CVSS 3.x base score 7.5)
• CVSS v2: 7.8
• EPSS exploit prediction: 3% (83rd percentile)
• Actively exploited: Not listed in CISA KEV
• Weakness: CWE-772
• Affected product: F5 Big-ip Access Policy Manager
• Published: 2018-06-27
• Last modified: 2026-06-17

Description

On BIG-IP 13.1.0-13.1.0.7, a remote attacker using undisclosed methods against virtual servers configured with a Client SSL or Server SSL profile that has the SSL Forward Proxy feature enabled can force the Traffic Management Microkernel (tmm) to leak memory. As a result, system memory usage increases over time, which may eventually cause a decrease in performance or a system reboot due to memory exhaustion.

Frequently asked questions

What is CVE-2018-5527?

On BIG-IP 13.1.0-13.1.0.7, a remote attacker using undisclosed methods against virtual servers configured with a Client SSL or Server SSL profile that has the SSL Forward Proxy feature enabled can force the Traffic Management Microkernel (tmm) to leak memory. As a result, system memory usage increases over time, which may eventually cause a decrease in performance or a system reboot due to memory exhaustion.

How severe is CVE-2018-5527?

CVE-2018-5527 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2018-5527 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (83rd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2018-5527?

CVE-2018-5527 primarily affects F5 Big-ip Access Policy Manager. In total, 13 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2018-5527?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2018-5527 published?

CVE-2018-5527 was published on 2018-06-27 and last updated on 2026-06-17.

References

• http://www.securitytracker.com/id/1041196
• https://support.f5.com/csp/article/K20134942

Affected products (13)

• cpe:2.3:a:f5:big-ip_access_policy_manager:*:*:*:*:*:*:*:*
• cpe:2.3:a:f5:big-ip_advanced_firewall_manager:*:*:*:*:*:*:*:*
• cpe:2.3:a:f5:big-ip_analytics:*:*:*:*:*:*:*:*
• cpe:2.3:a:f5:big-ip_application_acceleration_manager:*:*:*:*:*:*:*:*
• cpe:2.3:a:f5:big-ip_application_security_manager:*:*:*:*:*:*:*:*
• cpe:2.3:a:f5:big-ip_domain_name_system:*:*:*:*:*:*:*:*
• cpe:2.3:a:f5:big-ip_edge_gateway:*:*:*:*:*:*:*:*
• cpe:2.3:a:f5:big-ip_global_traffic_manager:*:*:*:*:*:*:*:*
• cpe:2.3:a:f5:big-ip_link_controller:*:*:*:*:*:*:*:*
• cpe:2.3:a:f5:big-ip_local_traffic_manager:*:*:*:*:*:*:*:*
• cpe:2.3:a:f5:big-ip_policy_enforcement_manager:*:*:*:*:*:*:*:*
• cpe:2.3:a:f5:big-ip_webaccelerator:*:*:*:*:*:*:*:*
• cpe:2.3:a:f5:big-ip_websafe:*:*:*:*:*:*:*:*

More vulnerabilities in F5 Big-ip Access Policy Manager

• CVE-2023-41373 — Critical (CVSS 9.9): A directory traversal vulnerability exists in the BIG-IP Configuration Utility that may allow an authenticated attacker…
• CVE-2021-22987 — Critical (CVSS 9.9): On BIG-IP versions 16.0.x before 16.0.1.1, 15.1.x before 15.1.2.1, 14.1.x before 14.1.4, 13.1.x before 13.1.3.6, 12.1.x…
• CVE-2025-53521 — Critical (CVSS 9.8): When a BIG-IP APM access policy is configured on a virtual server, specific malicious traffic can lead to Remote Code…
• CVE-2023-46747 — Critical (CVSS 9.8): Undisclosed requests may bypass configuration utility authentication, allowing an attacker with network access to the…
• CVE-2022-1388 — Critical (CVSS 9.8): On F5 BIG-IP 16.1.x versions prior to 16.1.2.2, 15.1.x versions prior to 15.1.5.1, 14.1.x versions prior to 14.1.4.6,…
• CVE-2021-23008 — Critical (CVSS 9.8): On version 15.1.x before 15.1.3, 14.1.x before 14.1.4, 13.1.x before 13.1.4, 12.1.x before 12.1.6, and all versions of…

All CVEs affecting F5 Big-ip Access Policy Manager →

Other CWE-772 vulnerabilities

• CVE-2020-12134 — Critical (CVSS 9.8): Nanometrics Centaur through 4.3.23 and TitanSMA through 4.2.20 mishandle access control for the syslog log.
• CVE-2017-15032 — Critical (CVSS 9.8): ImageMagick version 7.0.7-2 contains a memory leak in ReadYCBCRImage in coders/ycbcr.c.
• CVE-2017-14138 — Critical (CVSS 9.8): ImageMagick 7.0.6-5 has a memory leak vulnerability in ReadWEBPImage in coders/webp.c because memory is not freed in…
• CVE-2017-11641 — Critical (CVSS 9.8): GraphicsMagick 1.3.26 has a Memory Leak in the PersistCache function in magick/pixel_cache.c during writing of Magick…
• CVE-2020-14339 — High (CVSS 8.8): A flaw was found in libvirt, where it leaked a file descriptor for `/dev/mapper/control` into the QEMU process. This…
• CVE-2018-19760 — High (CVSS 8.8): cfg_init in confuse.c in libConfuse 3.2.2 has a memory leak.

Browse all CWE-772 vulnerabilities →