VulnerabilityModified

CVE-2009-4171

Messenger 9.0.0.2162, and possibly other 9.0 versions, allows remote attackers to cause a denial of service (NULL pointer dereference and application crash) by calling the RegisterMe method with a long argument.

EXPLOIT ×2 ✓MEDIUM 4.3EPSS 5.09%

Does this matter?

2 public exploits are published in Exploit-DB (verified), so the technical barrier is gone even though the severity is medium and EPSS is 5.1%. Treat it as high on anything reachable from the internet.

Description

An ActiveX control in YahooBridgeLib.dll for Yahoo! Messenger 9.0.0.2162, and possibly other 9.0 versions, allows remote attackers to cause a denial of service (NULL pointer dereference and application crash) by calling the RegisterMe method with a long argument.

CVSS 2.0: 4.3 MEDIUMAV:N/AC:M/Au:N/C:N/I:N/A:P
EPSS: 5.09% probability · 92th percentile
Public exploits: 2 in Exploit-DB · verified · first 12 November 2009
CISA KEV: Not listed
Weakness: CWE-119
Affected: yahoo/messenger
Source: cve@mitre.org

EPSS trend

EPSS 5.1% since 26 October 2026; no change recorded yet. The dashed line is the ten per cent mark our analysts treat as “patch before the next change window”. Points are recorded when the score first appears and whenever it moves by a percentage point or more.

Public exploits (2)

Entries in Exploit-DB that cite this CVE. Links go to the Exploit-DB page and to the file in the public repository; nothing is hosted here. A verified tick means the Exploit-DB team confirmed the exploit works against the stated version.

EDB-ID	Title	Type	Published	Verified
EDB-33350 source ↗	Yahoo! Messenger 9 - 'YahooBridgeLib.dll' ActiveX Control Remote Denial of Servicewindows · HACKATTACK	dos	12 November 2009	yes
EDB-10092 source ↗	Yahoo! Messenger 9.0.0.2162 - 'YahooBridgeLib.dll' ActiveX Control Remote Denial of Servicewindows · HACKATTACK	dos	12 November 2009	yes

References

Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.