CVE-2009-4893

Buffer overflow in UnrealIRCd 3.2beta11 through 3.2.8, when allow::options::noident is enabled, allows remote attackers to cause a denial of service (crash) and possibly execute arbitrary code via unspecified vectors.

Published: 2010-06-15 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2009-4893 is rated Moderate Risk (57/100): CVSS Medium severity, with medium exploitation likelihood (EPSS 2.51%). 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-2009-4893

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 1.67% 2.51% +0.84%
2 2025-03-30 1.48% 1.67% +0.19%
3 2025-03-29 — 1.48% —

Full EPSS history (10 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2009-4893

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
6.8 2.0 MEDIUM
AV:N/AC:M/Au:N/C:P/I:P/A:P Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:M)
Exploitation needs some favorable conditions, but not exceptional ones.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:P)
Partial integrity impact.
Availability impact (A:P)
Partial availability impact.
 8.6 6.4 [email protected]

Weakness enumeration for CVE-2009-4893

OS Trackers for CVE-2009-4893

vendor priority summary link
gentoo high CVE-2009-4893: 1 GLSA(s) (201006-21), 1 atom(s) (net-irc/unrealircd); latest impact high. https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2009-4893

Affected software / configurations for CVE-2009-4893

Vendor Product Version Raw CPE
unrealircd unrealircd 3.2 cpe:2.3:a:unrealircd:unrealircd:3.2:beta11:*:*:*:*:*:*
unrealircd unrealircd 3.2.1 cpe:2.3:a:unrealircd:unrealircd:3.2.1:*:*:*:*:*:*:*
unrealircd unrealircd 3.2.1 cpe:2.3:a:unrealircd:unrealircd:3.2.1:pre1:*:*:*:*:*:*
unrealircd unrealircd 3.2.1 cpe:2.3:a:unrealircd:unrealircd:3.2.1:pre2:*:*:*:*:*:*
unrealircd unrealircd 3.2.2 cpe:2.3:a:unrealircd:unrealircd:3.2.2:*:*:*:*:*:*:*
unrealircd unrealircd 3.2.2 cpe:2.3:a:unrealircd:unrealircd:3.2.2:pre1:*:*:*:*:*:*
unrealircd unrealircd 3.2.3 cpe:2.3:a:unrealircd:unrealircd:3.2.3:*:*:*:*:*:*:*
unrealircd unrealircd 3.2.3 cpe:2.3:a:unrealircd:unrealircd:3.2.3:pre1:*:*:*:*:*:*
unrealircd unrealircd 3.2.3 cpe:2.3:a:unrealircd:unrealircd:3.2.3:pre2:*:*:*:*:*:*
unrealircd unrealircd 3.2.3 cpe:2.3:a:unrealircd:unrealircd:3.2.3:pre3:*:*:*:*:*:*
unrealircd unrealircd 3.2.3 cpe:2.3:a:unrealircd:unrealircd:3.2.3:pre4:*:*:*:*:*:*
unrealircd unrealircd 3.2.4 cpe:2.3:a:unrealircd:unrealircd:3.2.4:*:*:*:*:*:*:*
unrealircd unrealircd 3.2.4 cpe:2.3:a:unrealircd:unrealircd:3.2.4:pre1:*:*:*:*:*:*
unrealircd unrealircd 3.2.4 cpe:2.3:a:unrealircd:unrealircd:3.2.4:pre2:*:*:*:*:*:*
unrealircd unrealircd 3.2.4 cpe:2.3:a:unrealircd:unrealircd:3.2.4:rc1:*:*:*:*:*:*
unrealircd unrealircd 3.2.4 cpe:2.3:a:unrealircd:unrealircd:3.2.4:rc2:*:*:*:*:*:*
unrealircd unrealircd 3.2.4 cpe:2.3:a:unrealircd:unrealircd:3.2.4:rc3:*:*:*:*:*:*
unrealircd unrealircd 3.2.5 cpe:2.3:a:unrealircd:unrealircd:3.2.5:*:*:*:*:*:*:*
unrealircd unrealircd 3.2.5 cpe:2.3:a:unrealircd:unrealircd:3.2.5:rc1:*:*:*:*:*:*
unrealircd unrealircd 3.2.5 cpe:2.3:a:unrealircd:unrealircd:3.2.5:rc2:*:*:*:*:*:*
unrealircd unrealircd 3.2.5 cpe:2.3:a:unrealircd:unrealircd:3.2.5:rc3:*:*:*:*:*:*
unrealircd unrealircd 3.2.6 cpe:2.3:a:unrealircd:unrealircd:3.2.6:*:*:*:*:*:*:*
unrealircd unrealircd 3.2.6 cpe:2.3:a:unrealircd:unrealircd:3.2.6:rc1:*:*:*:*:*:*
unrealircd unrealircd 3.2.6 cpe:2.3:a:unrealircd:unrealircd:3.2.6:rc2:*:*:*:*:*:*
unrealircd unrealircd 3.2.6 cpe:2.3:a:unrealircd:unrealircd:3.2.6:rc3:*:*:*:*:*:*
unrealircd unrealircd 3.2.7 cpe:2.3:a:unrealircd:unrealircd:3.2.7:*:*:*:*:*:*:*
unrealircd unrealircd 3.2.7 cpe:2.3:a:unrealircd:unrealircd:3.2.7:rc1:*:*:*:*:*:*
unrealircd unrealircd 3.2.7 cpe:2.3:a:unrealircd:unrealircd:3.2.7:rc2:*:*:*:*:*:*
unrealircd unrealircd 3.2.8 cpe:2.3:a:unrealircd:unrealircd:3.2.8:*:*:*:*:*:*:*
unrealircd unrealircd 3.2.8 cpe:2.3:a:unrealircd:unrealircd:3.2.8:rc1:*:*:*:*:*:*
unrealircd unrealircd 3.2.8 cpe:2.3:a:unrealircd:unrealircd:3.2.8:rc2:*:*:*:*:*:*

References for CVE-2009-4893

cvelogic Threat Intelligence