CVE-2017-12311

A vulnerability in the H.264 decoder function of Cisco Meeting Server could allow an unauthenticated, remote attacker to cause a Cisco Meeting Server media process to restart unexpectedly when it receives an illegal H.264 frame. The vulnerability is triggered by an H.264 frame that has an invalid picture parameter set (PPS) value. An attacker could exploit this vulnerability by sending a malformed H.264 frame to the targeted device. An exploit could allow the attacker to cause a denial of service (DoS) condition because the media process could restart. The media session should be re-established within a few seconds, during which there could be a brief interruption in service. Cisco Bug IDs: CSCvg12559.

Published: 2017-11-16 Last update: 2026-05-13 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2017-12311 is rated Moderate Risk (52.6/100): CVSS Medium severity, with medium exploitation likelihood (EPSS 2.20%). EPSS rose +1.38% over the last day, indicating growing attacker interest. 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-2017-12311

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 0.82% 2.20% +1.38%
2 2025-03-30 1.08% 0.82% -0.26%
3 2025-03-29 — 1.08% —

Full EPSS history (9 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2017-12311

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
5.8 3.0 MEDIUM
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:L 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:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:L)
Might cause slowdowns, glitches, or partial disruption—not a full brick.
 3.9 1.4 [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-2017-12311

Affected software / configurations for CVE-2017-12311

Vendor Product Version Raw CPE
cisco meeting_server 2.0 cpe:2.3:a:cisco:meeting_server:2.0:*:*:*:*:*:*:*
cisco meeting_server 2.1.0 cpe:2.3:a:cisco:meeting_server:2.1.0:*:*:*:*:*:*:*
cisco meeting_server 2.2.0 cpe:2.3:a:cisco:meeting_server:2.2.0:*:*:*:*:*:*:*
cisco meeting_server 2.3.0 cpe:2.3:a:cisco:meeting_server:2.3.0:*:*:*:*:*:*:*

References for CVE-2017-12311

cvelogic Threat Intelligence