CVE-2009-1915: Stack-based buffer overflow in the URL Search Hook (ICQToolBar.dll) in ICQ 6.5 allows remote attackers to caus

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MEDIUM 4.3DOWNGRADE

CVE-2009-1915 is a medium-severity flaw (CVSS 4.3) affecting icq. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Stack-based buffer overflow in the URL Search Hook (ICQToolBar.dll) in ICQ 6.5 allows remote attackers to cause a denial of service (persistent crash) and possibly execute arbitrary code via an Internet shortcut .URL file containing a long URL parameter, which triggers a crash when browsing a folder that contains this file.

Why this priority

EPSS top 8%: very likely to be exploited
Public exploit reference

No fix is published yet: follow the downgrade or mitigation steps.

Risk facts

CVSS score	4.3 (Medium)
EPSS exploit chance	5.0% (top 8%)
CISA exploited list	No
Weakness	CWE-119
Published	2009-06-04
Last modified	2026-06-16

Publisher (CNA): MITRE · Vendor: icq

Last updated 2026-06-16 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2009-06-04 17:30 UTCPublished CVE record published
2026-06-16 23:08 UTCUpdated Record last modified

icq icq DOWNGRADE

Affected: 6.5

Fixed in: no fixed release known

Safe to downgrade to: a release before 6.5

1. Check installed version

apt-cache policy icq || rpm -q icq || icq --version

2. No fixed release: DOWNGRADE to a release before 6.5 (Debian / Ubuntu)

apt-cache madison icq sudo apt install icq=<VERSION_BEFORE_6.5> sudo apt-mark hold icq

2. No fixed release: DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list icq sudo dnf downgrade icq-<VERSION_BEFORE_6.5> sudo dnf versionlock add icq

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Public exploits and detection

Public code exists for this CVE. Treat unpatched systems as at risk, and only run PoCs in a lab.

Exploit-DB: ICQ 6.5 - URL Search Hook (Windows Explorer) Remote Buffer Overflow (PoC)

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2009-1915?

icq: downgrade or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2009-1915 being exploited?

CVE-2009-1915 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2009-1915 affect?

CVE-2009-1915 affects icq. Severity is medium (CVSS 4.3). Stack-based buffer overflow in the URL Search Hook (ICQToolBar.dll) in ICQ 6.5 allows remote attackers to cause a denial of service (persistent crash) and possibly execute arbitrary code via an Internet shortcut .URL file containing a long

How urgent is CVE-2009-1915?

Priority 43/100. EPSS top 8%: very likely to be exploited; Public exploit reference

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References

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