How severe is CVE-2008-5520?

CVE-2008-5520 has a CVSS 2.0 base score of 9.3, rated critical severity.

Is CVE-2008-5520 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (78th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2008-5520?

CVE-2008-5520 primarily affects Ahnlab V3 Internet Security. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2008-5520?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

When was CVE-2008-5520 published?

CVE-2008-5520 was published on 2008-12-12 and last updated on 2026-06-16.

CVE-2008-5520

CVE-2008-5520 is a critical-severity vulnerability in Ahnlab V3 Internet Security with a CVSS 2.0 base score of 9.3. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-20.

Key facts

Severity: Critical (CVSS 2.0 base score 9.3)
EPSS exploit prediction: 2% (78th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-20
Affected product: Ahnlab V3 Internet Security
Published: 2008-12-12
Last modified: 2026-06-16

Description

AhnLab V3 2008.12.4.1 and possibly 2008.9.13.0, when Internet Explorer 6 or 7 is used, allows remote attackers to bypass detection of malware in an HTML document by placing an MZ header (aka "EXE info") at the beginning, and modifying the filename to have (1) no extension, (2) a .txt extension, or (3) a .jpg extension, as demonstrated by a document containing a CVE-2006-5745 exploit.

Frequently asked questions

What is CVE-2008-5520?: AhnLab V3 2008.12.4.1 and possibly 2008.9.13.0, when Internet Explorer 6 or 7 is used, allows remote attackers to bypass detection of malware in an HTML document by placing an MZ header (aka "EXE info") at the beginning, and modifying the filename to have (1) no extension, (2) a .txt extension, or (3) a .jpg extension, as demonstrated by a document containing a CVE-2006-5745 exploit.
How severe is CVE-2008-5520?: CVE-2008-5520 has a CVSS 2.0 base score of 9.3, rated critical severity.
Is CVE-2008-5520 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (78th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2008-5520?: CVE-2008-5520 primarily affects Ahnlab V3 Internet Security. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2008-5520?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2008-5520 published?: CVE-2008-5520 was published on 2008-12-12 and last updated on 2026-06-16.

References

Affected products (2)

cpe:2.3:a:ahnlab:v3_internet_security:2008.9.13.0:*:*:*:*:*:*:*
cpe:2.3:a:ahnlab:v3_internet_security:2008.12.4.1:*:*:*:*:*:*:*

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