CVE-2003-0556

Polycom MGC 25 allows remote attackers to cause a denial of service (crash) via a large number of "user" requests to the control port 5003, as demonstrated using the blast TCP stress tester.

Published: 2003-08-18 Last update: 2026-04-16 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2003-0556 is rated Moderate Risk (44.6/100): CVSS Medium severity, with medium exploitation likelihood (EPSS 0.66%). 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-2003-0556

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 2025-03-17 0.33% 0.66% +0.33%
2 2023-03-07 1.05% 0.33% -0.73%
3 2022-02-04 1.05%

Full EPSS history (3 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2003-0556

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
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-2003-0556

Affected software / configurations for CVE-2003-0556

Vendor Product Version Raw CPE
polycom mgc-100 cpe:2.3:h:polycom:mgc-100:*:*:*:*:*:*:*:*
polycom mgc-25 5.51.21 cpe:2.3:h:polycom:mgc-25:5.51.21:*:*:*:*:*:*:*
polycom mgc-25 5.51.211 cpe:2.3:h:polycom:mgc-25:5.51.211:*:*:*:*:*:*:*
polycom mgc-50 cpe:2.3:h:polycom:mgc-50:*:*:*:*:*:*:*:*

References for CVE-2003-0556

cvelogic Threat Intelligence