HOMEVULNERABILITIESCVE-2009-1959
MEDIUMPOC

CVE-2009-1959

CWE-189Published: June 8, 2009· Updated: Jun 16, 2026

5.0
CVSS v3.1

Official Description

Off-by-one error in the event_wallops function in fe-common/irc/fe-events.c in irssi 0.8.13 allows remote IRC servers to cause a denial of service (crash) via an empty command, which triggers a one-byte buffer under-read and a one-byte buffer underflow.

NVD Source

Technical Analysis

CVE-2009-1959 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

Exploitation requires some privileges, which limits the exposure to scenarios where an attacker has already gained initial access.

A proof-of-concept (PoC) exploit exists for CVE-2009-1959. While not yet confirmed in active campaigns, the availability of PoC code increases exploitation risk substantially.

CVSS v3.1 Vector Breakdown

Exploitability
Attack VectorNetwork
Attack ComplexityLow
Privileges Req.
User Interaction
Scope
Impact
ConfidentialityNone
IntegrityNone
AvailabilityP
AV:N/AC:L/Au:N/C:N/I:N/A:P

Affected Vendors & Products

irssi1 product(s)
irssi
Source: NVD CPE · 1 total CPE entries

Exploit & PoC Resources

POC AVAILABLEProof-of-concept code exists
Exploit-DB
Offensive Security exploit database
GitHub PoC Search
Community PoC repositories
Rapid7 / Metasploit
Metasploit module search
PacketStorm
Security advisories & exploits
NVD Detail
Official NIST entry
MITRE CVE
CVE Program entry
External links open in a new tab. Always verify in a controlled environment before use.

Official Patches & Advisories

ADVISORYhttp://bugs.irssi.org/index.php?do=details&task_id=662
ADVISORYhttp://www.irssi.org/ChangeLog
ADVISORYhttp://bugs.irssi.org/index.php?do=details&task_id=662
ADVISORYhttp://www.irssi.org/ChangeLog

All References (30)

→
http://bugs.irssi.org/index.php?do=details&task_id=662Exploit · Vendor Advisory
→
http://lists.opensuse.org/opensuse-security-announce/2009-07/msg00002.html
→
http://secunia.com/advisories/35685
→
http://secunia.com/advisories/35812
→
http://secunia.com/advisories/36152
→
http://www.irssi.org/ChangeLogExploit · Vendor Advisory
→
http://www.mandriva.com/security/advisories?name=MDVSA-2009:133
→
http://www.openwall.com/lists/oss-security/2009/05/29/3
→
http://www.securityfocus.com/bid/35399
→
http://www.securitytracker.com/id?1022410
→
http://www.ubuntu.com/usn/usn-800-1
→
http://www.vupen.com/english/advisories/2009/1596
→
http://xorl.wordpress.com/2009/05/28/irssi-event_wallops-off-by-one-readwrite/Exploit
→
https://exchange.xforce.ibmcloud.com/vulnerabilities/51184
→
https://www.redhat.com/archives/fedora-package-announce/2009-August/msg00146.html

Quick Facts

CVE IDCVE-2009-1959
CVSS Score5.0 / 10
SeverityMEDIUM
WeaknessCWE-189
CISA KEVNo
ExploitPOC
Affected1 vendor(s)
PublishedJun 8, 2009

Related CVEs (CWE-189)

CVE-2006-5940
10.0
CVE-2009-1301
10.0
CVE-2008-5284
10.0
CVE-2008-1842
10.0
CVE-2009-2463
10.0
CVE-2008-2654
10.0

Recommended Actions

  • →Apply vendor patches immediately
  • →Monitor CVE-2009-1959 in threat intel feeds
  • →Review IDS/IPS signatures for exploitation attempts
Data sourced from NVD (NIST), CISA KEV, and EPSS (FIRST). Analysis generated by CTIWATCH.COM. CVE data is provided under the NVD usage policy.
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