CVE-2016-6466

A vulnerability in the IPsec component of StarOS for Cisco ASR 5000 Series routers could allow an unauthenticated, remote attacker to terminate all active IPsec VPN tunnels and prevent new tunnels from establishing, resulting in a denial of service (DoS) condition. This vulnerability affects the following Cisco products: Cisco ASR 5000/5500 Series routers, Cisco Virtualized Packet Core (VPC). More Information: CSCva13631. Known Affected Releases: 20.0.0 20.1.0 20.2.0 20.2.3 20.2.v1 21.0.0 21.0.M0.64246. Known Fixed Releases: 20.2.3 20.2.3.65026 20.2.a4.65307 20.2.v1 20.2.v1.65353 20.3.M0.65037 20.3.T0.65043 21.0.0 21.0.0.65256 21.0.M0.64595 21.0.M0.64860 21.0.M0.65140 21.0.V0.65052 21.0.V0.65150 21.0.V0.65366 21.0.VC0.64639 21.1.A0.64861 21.1.A0.65145 21.1.PP0.65270 21.1.R0.65130 21.1.R0.65135 21.1.R0.65154 21.1.VC0.64898 21.1.VC0.65203 21.2.A0.65147.

Published: 2016-11-18 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2016-6466 is rated Moderate Risk (60.9/100): CVSS High severity, with medium exploitation likelihood (EPSS 2.58%). Core evidence: EPSS rose +1.81% 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-2016-6466

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 0.78% 2.58% +1.81%
2 2025-03-30 1.47% 0.78% -0.70%
3 2025-03-29 1.47%

Full EPSS history (6 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2016-6466

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-2016-6466

Affected software / configurations for CVE-2016-6466

Vendor Product Version Raw CPE
cisco asr_5000_series_software 20.0.0 cpe:2.3:a:cisco:asr_5000_series_software:20.0.0:*:*:*:*:*:*:*
cisco asr_5000_series_software 20.0.2.3 cpe:2.3:a:cisco:asr_5000_series_software:20.0.2.3:*:*:*:*:*:*:*
cisco asr_5000_series_software 20.0.2.v1 cpe:2.3:a:cisco:asr_5000_series_software:20.0.2.v1:*:*:*:*:*:*:*
cisco virtualized_packet_core 20.0_base cpe:2.3:a:cisco:virtualized_packet_core:20.0_base:*:*:*:*:*:*:*

References for CVE-2016-6466

cvelogic Threat Intelligence