How severe is CVE-2009-3523?

CVE-2009-3523 has a CVSS 2.0 base score of 6.9, rated medium severity.

Is CVE-2009-3523 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (52nd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2009-3523?

CVE-2009-3523 primarily affects Avast Avast Antivirus Home. In total, 29 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2009-3523?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2009-3523 published?

CVE-2009-3523 was published on 2009-10-01 and last updated on 2026-06-16.

CVE-2009-3523

CVE-2009-3523 is a medium-severity vulnerability in Avast Avast Antivirus Home with a CVSS 2.0 base score of 6.9. 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: Medium (CVSS 2.0 base score 6.9)
EPSS exploit prediction: 1% (52nd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-20
Affected product: Avast Avast Antivirus Home
Published: 2009-10-01
Last modified: 2026-06-16

Description

aavmKer4.sys in avast! Home and Professional for Windows before 4.8.1356 does not properly validate input to IOCTLs (1) 0xb2d6000c and (2) 0xb2d60034, which allows local users to gain privileges via IOCTL requests using crafted kernel addresses that trigger memory corruption, a different vulnerability than CVE-2008-1625.

Frequently asked questions

What is CVE-2009-3523?: aavmKer4.sys in avast! Home and Professional for Windows before 4.8.1356 does not properly validate input to IOCTLs (1) 0xb2d6000c and (2) 0xb2d60034, which allows local users to gain privileges via IOCTL requests using crafted kernel addresses that trigger memory corruption, a different vulnerability than CVE-2008-1625.
How severe is CVE-2009-3523?: CVE-2009-3523 has a CVSS 2.0 base score of 6.9, rated medium severity.
Is CVE-2009-3523 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (52nd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2009-3523?: CVE-2009-3523 primarily affects Avast Avast Antivirus Home. In total, 29 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2009-3523?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2009-3523 published?: CVE-2009-3523 was published on 2009-10-01 and last updated on 2026-06-16.

References

Affected products (29)

cpe:2.3:a:avast:avast_antivirus_home:*:*:windows:*:*:*:*:*
cpe:2.3:a:avast:avast_antivirus_home:4.7.827:*:windows:*:*:*:*:*
cpe:2.3:a:avast:avast_antivirus_home:4.7.844:*:windows:*:*:*:*:*
cpe:2.3:a:avast:avast_antivirus_home:4.7.869:*:windows:*:*:*:*:*
cpe:2.3:a:avast:avast_antivirus_home:4.7.1043:*:windows:*:*:*:*:*
cpe:2.3:a:avast:avast_antivirus_home:4.7.1098:*:windows:*:*:*:*:*
cpe:2.3:a:avast:avast_antivirus_home:4.8.1169:*:windows:*:*:*:*:*
cpe:2.3:a:avast:avast_antivirus_home:4.8.1195:*:windows:*:*:*:*:*
cpe:2.3:a:avast:avast_antivirus_home:4.8.1201:*:windows:*:*:*:*:*
cpe:2.3:a:avast:avast_antivirus_home:4.8.1227:*:windows:*:*:*:*:*
cpe:2.3:a:avast:avast_antivirus_home:4.8.1229:*:windows:*:*:*:*:*
cpe:2.3:a:avast:avast_antivirus_home:4.8.1282:*:windows:*:*:*:*:*
cpe:2.3:a:avast:avast_antivirus_home:4.8.1290:*:windows:*:*:*:*:*
cpe:2.3:a:avast:avast_antivirus_home:4.8.1296:*:windows:*:*:*:*:*
cpe:2.3:a:avast:avast_antivirus_home:4.8.1335:*:windows:*:*:*:*:*
cpe:2.3:a:avast:avast_antivirus_professional:*:*:windows:*:*:*:*:*
cpe:2.3:a:avast:avast_antivirus_professional:4.7.827:*:windows:*:*:*:*:*
cpe:2.3:a:avast:avast_antivirus_professional:4.7.844:*:windows:*:*:*:*:*
cpe:2.3:a:avast:avast_antivirus_professional:4.7.1043:*:windows:*:*:*:*:*
cpe:2.3:a:avast:avast_antivirus_professional:4.7.1098:*:windows:*:*:*:*:*
cpe:2.3:a:avast:avast_antivirus_professional:4.8.1169:*:windows:*:*:*:*:*
cpe:2.3:a:avast:avast_antivirus_professional:4.8.1195:*:windows:*:*:*:*:*
cpe:2.3:a:avast:avast_antivirus_professional:4.8.1201:*:windows:*:*:*:*:*
cpe:2.3:a:avast:avast_antivirus_professional:4.8.1227:*:windows:*:*:*:*:*
cpe:2.3:a:avast:avast_antivirus_professional:4.8.1229:*:windows:*:*:*:*:*
cpe:2.3:a:avast:avast_antivirus_professional:4.8.1282:*:windows:*:*:*:*:*
cpe:2.3:a:avast:avast_antivirus_professional:4.8.1290:*:windows:*:*:*:*:*
cpe:2.3:a:avast:avast_antivirus_professional:4.8.1296:*:windows:*:*:*:*:*
cpe:2.3:a:avast:avast_antivirus_professional:4.8.1335:*:windows:*:*:*:*:*

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