How severe is CVE-2022-4291?

CVE-2022-4291 has a CVSS 3.x base score of 7.7, rated high severity. It is exploitable over local access with high attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability low.

Is CVE-2022-4291 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (34th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2022-4291?

CVE-2022-4291 affects Avast Script Shield. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2022-4291?

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

When was CVE-2022-4291 published?

CVE-2022-4291 was published on 2022-12-08 and last updated on 2026-06-17.

CVE-2022-4291

CVE-2022-4291 is a high-severity vulnerability in Avast Script Shield with a CVSS 3.x base score of 7.7. 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-787.

Key facts

Severity: High (CVSS 3.x base score 7.7)
EPSS exploit prediction: 0% (34th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-787
Affected product: Avast Script Shield
Published: 2022-12-08
Last modified: 2026-06-17

Description

The aswjsflt.dll library from Avast Antivirus windows contained a potentially exploitable heap corruption vulnerability that could enable an attacker to bypass the sandbox of the application it was loaded into, if applicable. This issue was fixed in version 18.0.1478 of the Script Shield Component.

Frequently asked questions

What is CVE-2022-4291?: The aswjsflt.dll library from Avast Antivirus windows contained a potentially exploitable heap corruption vulnerability that could enable an attacker to bypass the sandbox of the application it was loaded into, if applicable. This issue was fixed in version 18.0.1478 of the Script Shield Component.
How severe is CVE-2022-4291?: CVE-2022-4291 has a CVSS 3.x base score of 7.7, rated high severity. It is exploitable over local access with high attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability low.
Is CVE-2022-4291 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (34th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2022-4291?: CVE-2022-4291 affects Avast Script Shield. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2022-4291?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2022-4291 published?: CVE-2022-4291 was published on 2022-12-08 and last updated on 2026-06-17.

References

https://support.norton.com/sp/static/external/tools/security-advisories.html

Affected products (1)

cpe:2.3:a:avast:script_shield:*:*:*:*:*:*:*:*

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