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CVE-2009-4016

19
FAUCET Score

CVE-2009-4016 describes an integer underflow vulnerability in the clean_string function of IRCD-hybrid, ircd-ratbox, and oftc-hybrid IRC daemons. This flaw, triggered by a crafted LINKS command when flatten_links is disabled, could allow remote attackers to execute arbitrary code or cause a denial of service. With a CVSS score of 6.8, it represents a medium-severity risk, requiring moderate attack complexity but no authentication, potentially leading to partial confidentiality, integrity, and availability impacts. There is no evidence of active exploitation, public exploit code (Metasploit, Nuclei, ExploitDB), or significant community discussion or media coverage surrounding this vulnerability.

Impacted Technologies

VendorProductVersion(s)CPE
7.2.2CPE matchmatch criteria
cpe:2.3:a:ircd-hybrid:ircd-hybrid:7.2.2:*:*:*:*:*:*:*
7.2.3CPE matchmatch criteria
cpe:2.3:a:ircd-hybrid:ircd-hybrid:7.2.3:*:*:*:*:*:*:*
<= 2.2.8CPE matchmatch criteria
cpe:2.3:a:ircd-ratbox:ircd-ratbox:*:*:*:*:*:*:*:*
1.0CPE matchmatch criteria
cpe:2.3:a:ircd-ratbox:ircd-ratbox:1.0:*:*:*:*:*:*:*
1.1CPE matchmatch criteria
cpe:2.3:a:ircd-ratbox:ircd-ratbox:1.1:*:*:*:*:*:*:*

CVSS Data

CVSS version used by this source: 2.0

6.8MEDIUM

AV:N/AC:M/Au:N/C:P/I:P/A:P

Confidentiality Impact
PARTIAL
Integrity Impact
PARTIAL
Availability Impact
PARTIAL
Access Vector
NETWORK
Access Complexity
MEDIUM
Authentication
NONE
Exploitability Score
8.6
Impact Score
6.4
CvssVersion
2.0

Exploit Intelligence

EPSS Score
4.03%
Probability of exploitation in next 30 days
EPSS Percentile
89.5%
Percentile rank of EPSS score among Peer Group
As of 2026-07-27
Model: v2026.06.15
This CVE's current EPSS score of 0.0403 is in the 86th percentile among its peer group of 19,955 CVEs.

Social Chatter

No social media mentions found for this CVE.

The average CVE in this peer group has 0.0 Twitter, 0.0 Reddit, 0.0 Bluesky, 0.0 Mastodon, and 0.2 GitHub mentions.

Media Mentions

No media coverage found for this CVE.

The average CVE in this peer group has 0.0 InfoSec Media, 0.0 Vendor Blog, and 0.0 Security Researcher mentions.

Remediation

Patch Available

Vendor Patches (1)

debianpatch availablevia nvd_reference
View patch

Vendor Advisories (1)

redhatCVE-2009-4016Critical

ircd-{hybrid,ratbox}: multiple vulnerabilities

Jan 27, 2010

References

lists.ratbox.org / pipermail/ircd-ratbox/2010-January/000891.html
secunia.com / advisories/38210
Vendor Advisory
secunia.com / advisories/38381
Vendor Advisory
secunia.com / advisories/38382
Vendor Advisory
secunia.com / advisories/38383
Vendor Advisory
security.debian.org / pool/updates/main/i/ircd-hybrid/ircd-hybrid_7.2.2.dfsg.2-4+lenny1.diff.gz
Patch
svn.ircd-hybrid.org / viewcvs.cgi
trac.oftc.net / projects/oftc-hybrid/browser/tags/oftc-hybrid-1.6.8/RELNOTES
debian.org / security/2010/dsa-1980
Patch
securityfocus.com / bid/37978