CVE-2009-0652

CVE-2009-0652 is a medium-severity vulnerability in Mozilla Firefox with a CVSS 2.0 base score of 5.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low.

Key facts

Description

The Internationalized Domain Names (IDN) blacklist in Mozilla Firefox 3.0.6 and other versions before 3.0.9; Thunderbird before 2.0.0.21; and SeaMonkey before 1.1.15 does not include box-drawing characters, which allows remote attackers to spoof URLs and conduct phishing attacks, as demonstrated by homoglyphs of the / (slash) and ? (question mark) characters in a subdomain of a .cn domain name, a different vulnerability than CVE-2005-0233. NOTE: some third parties claim that 3.0.6 is not affected, but much older versions perhaps are affected.

Frequently asked questions

What is CVE-2009-0652?
The Internationalized Domain Names (IDN) blacklist in Mozilla Firefox 3.0.6 and other versions before 3.0.9; Thunderbird before 2.0.0.21; and SeaMonkey before 1.1.15 does not include box-drawing characters, which allows remote attackers to spoof URLs and conduct phishing attacks, as demonstrated by homoglyphs of the / (slash) and ? (question mark) characters in a subdomain of a .cn domain name, a different vulnerability than CVE-2005-0233. NOTE: some third parties claim that 3.0.6 is not affected, but much older versions perhaps are affected.
How severe is CVE-2009-0652?
CVE-2009-0652 has a CVSS 2.0 base score of 5.8, rated medium severity.
Is CVE-2009-0652 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (71st percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2009-0652?
CVE-2009-0652 primarily affects Mozilla Firefox. In total, 88 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2009-0652?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2009-0652 published?
CVE-2009-0652 was published on 2009-02-20 and last updated on 2026-06-16.

References

Affected products (88)

More vulnerabilities in Mozilla Firefox

All CVEs affecting Mozilla Firefox →