CVE-2016-5736

The default configuration of the IPsec IKE peer listener in F5 BIG-IP LTM, Analytics, APM, ASM, and Link Controller 11.2.1 before HF16, 11.4.x, 11.5.x before 11.5.4 HF2, 11.6.x before 11.6.1, and 12.x before 12.0.0 HF2; BIG-IP AAM, AFM, and PEM 11.4.x, 11.5.x before 11.5.4 HF2, 11.6.x before 11.6.1, and 12.x before 12.0.0 HF2; BIG-IP DNS 12.x before 12.0.0 HF2; BIG-IP Edge Gateway, WebAccelerator, and WOM 11.2.1 before HF16; BIG-IP GTM 11.2.1 before HF16, 11.4.x, 11.5.x before 11.5.4 HF2, and 11.6.x before 11.6.1; and BIG-IP PSM 11.4.0 through 11.4.1 improperly enables the anonymous IPsec IKE peer configuration object, which allows remote attackers to establish an IKE Phase 1 negotiation and possibly conduct brute-force attacks against Phase 2 negotiations via unspecified vectors.

Published: 2016-08-19 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2016-5736 is rated Moderate Risk (59.4/100): CVSS High severity, with medium exploitation likelihood (EPSS 2.27%). Core evidence: EPSS rose +1.14% over the last day, indicating growing attacker interest. Mandatory action: Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2016-5736

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 1.13% 2.27% +1.14%
2 2025-09-14 1.49% 1.13% -0.36%
3 2025-03-30 1.49%

Full EPSS history (9 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2016-5736

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.5 3.0 HIGH
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
3.9 3.6 [email protected]
5.0 2.0 MEDIUM
AV:N/AC:L/Au:N/C:N/I:N/A:P Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:N)
No confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:P)
Partial availability impact.
10.0 2.9 [email protected]

Weakness enumeration for CVE-2016-5736

Affected software / configurations for CVE-2016-5736

Vendor Product Version Raw CPE
f5 big-ip_application_acceleration_manager 11.4.0 cpe:2.3:a:f5:big-ip_application_acceleration_manager:11.4.0:*:*:*:*:*:*:*
f5 big-ip_application_acceleration_manager 11.4.1 cpe:2.3:a:f5:big-ip_application_acceleration_manager:11.4.1:*:*:*:*:*:*:*
f5 big-ip_application_acceleration_manager 11.5.0 cpe:2.3:a:f5:big-ip_application_acceleration_manager:11.5.0:*:*:*:*:*:*:*
f5 big-ip_application_acceleration_manager 11.5.1 cpe:2.3:a:f5:big-ip_application_acceleration_manager:11.5.1:*:*:*:*:*:*:*
f5 big-ip_application_acceleration_manager 11.5.2 cpe:2.3:a:f5:big-ip_application_acceleration_manager:11.5.2:*:*:*:*:*:*:*
f5 big-ip_application_acceleration_manager 11.5.3 cpe:2.3:a:f5:big-ip_application_acceleration_manager:11.5.3:*:*:*:*:*:*:*
f5 big-ip_application_acceleration_manager 11.5.4 cpe:2.3:a:f5:big-ip_application_acceleration_manager:11.5.4:*:*:*:*:*:*:*
f5 big-ip_application_acceleration_manager 11.6.0 cpe:2.3:a:f5:big-ip_application_acceleration_manager:11.6.0:*:*:*:*:*:*:*
f5 big-ip_application_acceleration_manager 12.0.0 cpe:2.3:a:f5:big-ip_application_acceleration_manager:12.0.0:*:*:*:*:*:*:*
f5 big-ip_webaccelerator 11.2.1 cpe:2.3:a:f5:big-ip_webaccelerator:11.2.1:*:*:*:*:*:*:*
f5 big-ip_analytics 11.2.1 cpe:2.3:a:f5:big-ip_analytics:11.2.1:*:*:*:*:*:*:*
f5 big-ip_analytics 11.4.0 cpe:2.3:a:f5:big-ip_analytics:11.4.0:*:*:*:*:*:*:*
f5 big-ip_analytics 11.4.1 cpe:2.3:a:f5:big-ip_analytics:11.4.1:*:*:*:*:*:*:*
f5 big-ip_analytics 11.5.0 cpe:2.3:a:f5:big-ip_analytics:11.5.0:*:*:*:*:*:*:*
f5 big-ip_analytics 11.5.1 cpe:2.3:a:f5:big-ip_analytics:11.5.1:*:*:*:*:*:*:*
f5 big-ip_analytics 11.5.2 cpe:2.3:a:f5:big-ip_analytics:11.5.2:*:*:*:*:*:*:*
f5 big-ip_analytics 11.5.3 cpe:2.3:a:f5:big-ip_analytics:11.5.3:*:*:*:*:*:*:*
f5 big-ip_analytics 11.5.4 cpe:2.3:a:f5:big-ip_analytics:11.5.4:*:*:*:*:*:*:*
f5 big-ip_analytics 11.6.0 cpe:2.3:a:f5:big-ip_analytics:11.6.0:*:*:*:*:*:*:*
f5 big-ip_analytics 12.0.0 cpe:2.3:a:f5:big-ip_analytics:12.0.0:*:*:*:*:*:*:*
f5 big-ip_domain_name_system 12.0.0 cpe:2.3:a:f5:big-ip_domain_name_system:12.0.0:*:*:*:*:*:*:*
f5 big-ip_edge_gateway 11.2.1 cpe:2.3:a:f5:big-ip_edge_gateway:11.2.1:*:*:*:*:*:*:*
f5 big-ip_access_policy_manager 11.2.1 cpe:2.3:a:f5:big-ip_access_policy_manager:11.2.1:*:*:*:*:*:*:*
f5 big-ip_access_policy_manager 11.4.0 cpe:2.3:a:f5:big-ip_access_policy_manager:11.4.0:*:*:*:*:*:*:*
f5 big-ip_access_policy_manager 11.4.1 cpe:2.3:a:f5:big-ip_access_policy_manager:11.4.1:*:*:*:*:*:*:*
f5 big-ip_access_policy_manager 11.5.0 cpe:2.3:a:f5:big-ip_access_policy_manager:11.5.0:*:*:*:*:*:*:*
f5 big-ip_access_policy_manager 11.5.1 cpe:2.3:a:f5:big-ip_access_policy_manager:11.5.1:*:*:*:*:*:*:*
f5 big-ip_access_policy_manager 11.5.2 cpe:2.3:a:f5:big-ip_access_policy_manager:11.5.2:*:*:*:*:*:*:*
f5 big-ip_access_policy_manager 11.5.3 cpe:2.3:a:f5:big-ip_access_policy_manager:11.5.3:*:*:*:*:*:*:*
f5 big-ip_access_policy_manager 11.5.4 cpe:2.3:a:f5:big-ip_access_policy_manager:11.5.4:*:*:*:*:*:*:*
f5 big-ip_access_policy_manager 11.6.0 cpe:2.3:a:f5:big-ip_access_policy_manager:11.6.0:*:*:*:*:*:*:*
f5 big-ip_access_policy_manager 12.0.0 cpe:2.3:a:f5:big-ip_access_policy_manager:12.0.0:*:*:*:*:*:*:*
f5 big-ip_local_traffic_manager 11.2.1 cpe:2.3:a:f5:big-ip_local_traffic_manager:11.2.1:*:*:*:*:*:*:*
f5 big-ip_local_traffic_manager 11.4.0 cpe:2.3:a:f5:big-ip_local_traffic_manager:11.4.0:*:*:*:*:*:*:*
f5 big-ip_local_traffic_manager 11.4.1 cpe:2.3:a:f5:big-ip_local_traffic_manager:11.4.1:*:*:*:*:*:*:*
f5 big-ip_local_traffic_manager 11.5.0 cpe:2.3:a:f5:big-ip_local_traffic_manager:11.5.0:*:*:*:*:*:*:*
f5 big-ip_local_traffic_manager 11.5.1 cpe:2.3:a:f5:big-ip_local_traffic_manager:11.5.1:*:*:*:*:*:*:*
f5 big-ip_local_traffic_manager 11.5.2 cpe:2.3:a:f5:big-ip_local_traffic_manager:11.5.2:*:*:*:*:*:*:*
f5 big-ip_local_traffic_manager 11.5.3 cpe:2.3:a:f5:big-ip_local_traffic_manager:11.5.3:*:*:*:*:*:*:*
f5 big-ip_local_traffic_manager 11.5.4 cpe:2.3:a:f5:big-ip_local_traffic_manager:11.5.4:*:*:*:*:*:*:*
f5 big-ip_local_traffic_manager 11.6.0 cpe:2.3:a:f5:big-ip_local_traffic_manager:11.6.0:*:*:*:*:*:*:*
f5 big-ip_local_traffic_manager 12.0.0 cpe:2.3:a:f5:big-ip_local_traffic_manager:12.0.0:*:*:*:*:*:*:*
f5 big-ip_advanced_firewall_manager 11.4.0 cpe:2.3:a:f5:big-ip_advanced_firewall_manager:11.4.0:*:*:*:*:*:*:*
f5 big-ip_advanced_firewall_manager 11.4.1 cpe:2.3:a:f5:big-ip_advanced_firewall_manager:11.4.1:*:*:*:*:*:*:*
f5 big-ip_advanced_firewall_manager 11.5.0 cpe:2.3:a:f5:big-ip_advanced_firewall_manager:11.5.0:*:*:*:*:*:*:*
f5 big-ip_advanced_firewall_manager 11.5.1 cpe:2.3:a:f5:big-ip_advanced_firewall_manager:11.5.1:*:*:*:*:*:*:*
f5 big-ip_advanced_firewall_manager 11.5.2 cpe:2.3:a:f5:big-ip_advanced_firewall_manager:11.5.2:*:*:*:*:*:*:*
f5 big-ip_advanced_firewall_manager 11.5.3 cpe:2.3:a:f5:big-ip_advanced_firewall_manager:11.5.3:*:*:*:*:*:*:*
f5 big-ip_advanced_firewall_manager 11.5.4 cpe:2.3:a:f5:big-ip_advanced_firewall_manager:11.5.4:*:*:*:*:*:*:*
f5 big-ip_advanced_firewall_manager 11.6.0 cpe:2.3:a:f5:big-ip_advanced_firewall_manager:11.6.0:*:*:*:*:*:*:*
f5 big-ip_advanced_firewall_manager 12.0.0 cpe:2.3:a:f5:big-ip_advanced_firewall_manager:12.0.0:*:*:*:*:*:*:*
f5 big-ip_websafe 11.6.0 cpe:2.3:a:f5:big-ip_websafe:11.6.0:*:*:*:*:*:*:*
f5 big-ip_websafe 12.0.0 cpe:2.3:a:f5:big-ip_websafe:12.0.0:*:*:*:*:*:*:*
f5 big-ip_policy_enforcement_manager 11.4.0 cpe:2.3:a:f5:big-ip_policy_enforcement_manager:11.4.0:*:*:*:*:*:*:*
f5 big-ip_policy_enforcement_manager 11.4.1 cpe:2.3:a:f5:big-ip_policy_enforcement_manager:11.4.1:*:*:*:*:*:*:*
f5 big-ip_policy_enforcement_manager 11.5.0 cpe:2.3:a:f5:big-ip_policy_enforcement_manager:11.5.0:*:*:*:*:*:*:*
f5 big-ip_policy_enforcement_manager 11.5.1 cpe:2.3:a:f5:big-ip_policy_enforcement_manager:11.5.1:*:*:*:*:*:*:*
f5 big-ip_policy_enforcement_manager 11.5.2 cpe:2.3:a:f5:big-ip_policy_enforcement_manager:11.5.2:*:*:*:*:*:*:*
f5 big-ip_policy_enforcement_manager 11.5.3 cpe:2.3:a:f5:big-ip_policy_enforcement_manager:11.5.3:*:*:*:*:*:*:*
f5 big-ip_policy_enforcement_manager 11.5.4 cpe:2.3:a:f5:big-ip_policy_enforcement_manager:11.5.4:*:*:*:*:*:*:*
f5 big-ip_policy_enforcement_manager 11.6.0 cpe:2.3:a:f5:big-ip_policy_enforcement_manager:11.6.0:*:*:*:*:*:*:*
f5 big-ip_policy_enforcement_manager 12.0.0 cpe:2.3:a:f5:big-ip_policy_enforcement_manager:12.0.0:*:*:*:*:*:*:*
f5 big-ip_global_traffic_manager 11.2.1 cpe:2.3:a:f5:big-ip_global_traffic_manager:11.2.1:*:*:*:*:*:*:*
f5 big-ip_global_traffic_manager 11.4.0 cpe:2.3:a:f5:big-ip_global_traffic_manager:11.4.0:*:*:*:*:*:*:*
f5 big-ip_global_traffic_manager 11.4.1 cpe:2.3:a:f5:big-ip_global_traffic_manager:11.4.1:*:*:*:*:*:*:*
f5 big-ip_global_traffic_manager 11.5.0 cpe:2.3:a:f5:big-ip_global_traffic_manager:11.5.0:*:*:*:*:*:*:*
f5 big-ip_global_traffic_manager 11.5.1 cpe:2.3:a:f5:big-ip_global_traffic_manager:11.5.1:*:*:*:*:*:*:*
f5 big-ip_global_traffic_manager 11.5.2 cpe:2.3:a:f5:big-ip_global_traffic_manager:11.5.2:*:*:*:*:*:*:*
f5 big-ip_global_traffic_manager 11.5.3 cpe:2.3:a:f5:big-ip_global_traffic_manager:11.5.3:*:*:*:*:*:*:*
f5 big-ip_global_traffic_manager 11.5.4 cpe:2.3:a:f5:big-ip_global_traffic_manager:11.5.4:*:*:*:*:*:*:*
f5 big-ip_global_traffic_manager 11.6.0 cpe:2.3:a:f5:big-ip_global_traffic_manager:11.6.0:*:*:*:*:*:*:*
f5 big-ip_link_controller 11.2.1 cpe:2.3:a:f5:big-ip_link_controller:11.2.1:*:*:*:*:*:*:*
f5 big-ip_link_controller 11.4.0 cpe:2.3:a:f5:big-ip_link_controller:11.4.0:*:*:*:*:*:*:*
f5 big-ip_link_controller 11.4.1 cpe:2.3:a:f5:big-ip_link_controller:11.4.1:*:*:*:*:*:*:*
f5 big-ip_link_controller 11.5.0 cpe:2.3:a:f5:big-ip_link_controller:11.5.0:*:*:*:*:*:*:*
f5 big-ip_link_controller 11.5.1 cpe:2.3:a:f5:big-ip_link_controller:11.5.1:*:*:*:*:*:*:*
f5 big-ip_link_controller 11.5.2 cpe:2.3:a:f5:big-ip_link_controller:11.5.2:*:*:*:*:*:*:*
f5 big-ip_link_controller 11.5.3 cpe:2.3:a:f5:big-ip_link_controller:11.5.3:*:*:*:*:*:*:*
f5 big-ip_link_controller 11.5.4 cpe:2.3:a:f5:big-ip_link_controller:11.5.4:*:*:*:*:*:*:*
f5 big-ip_link_controller 11.6.0 cpe:2.3:a:f5:big-ip_link_controller:11.6.0:*:*:*:*:*:*:*

References for CVE-2016-5736

cvelogic Threat Intelligence