TI-2020-13764 Aliases CVE-2020-20118 GHSA-qjj5-85f7-r9rp

Buffer Overflow vulnerability in Avast AntiVirus before v.19.7 allows a local attacker to…

LOW 24CWE-120Published 2023-07-11 · Updated 2026-07-09

Key facts

Attack vector: Local
Privileges required: Low
User interaction: None
Attack complexity: Low
Impact type: Denial of service
Confidentiality · integrity · availability: None · None · High
Fix status: No fix listed

Attack profile from CVSS 3.1 · NVD. Fix status from CNA. Impact type from CWE-120 and the CVSS impact.

Summary

Buffer Overflow vulnerability in Avast AntiVirus before v.19.7 allows a local attacker to cause a denial of service via a crafted request to the aswSnx.sys driver.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV

EPSS 0.00165 5th percentileScored 2026-11-07

Fix No fix listed No fixed version in the sources yet

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation: None
Automatable: No
Technical impact: Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

Vendor	Product	Affected versions	Fixed in	Status	Source
—	—	all versions	—	No fix listed	CNA

— Vendor— Affected all versions Fixed in — No fix listed CNA

CPE configurations NVD · 1

CPE	Versions	Role	Vendor
cpe:2.3:a:avast:antivirus::::::::	before 19.7	Vulnerable	Avast

cpe:2.3:a:avast:antivirus:*:*:*:*:*:*:*:* Versions before 19.7 Vulnerable ·Avast

Remediation

No fixed version listed by the sources yet.

Timeline

2026-10-02 Threatist record created from CVE-2020-20118
2026-10-03 Alias added: GHSA-qjj5-85f7-r9rp

References

Patch 1

https://gitlab.com/yongchuank/avast-aswsnx-ioctl-82ac0060-oob-write

TI-2020-08753 An issue was discovered in Avast Antivirus before 20. CVSS 3.1CRITICAL 9.8
TI-2017-05872 In Avast Antivirus before v17, using the LPC interface API exposed by the AvastSVC.exe… CVSS 3.0CRITICAL 9.8
TI-2025-03074 Integer Overflow in Avast Antiviurs 25.1.981.6 on Windows may result in privilege escalation CVSS 3.1CRITICAL 9.8
TI-2025-11929 Time-of-check time-of-use race condition in Avast Antivirus CVSS 3.1CRITICAL 9.9
TI-2021-20488 Privilege escalation vulnerability in the Self-Defense driver of Avast Antivirus prior to… CVSS 3.1HIGH 8.8
TI-2021-20487 Privilege escalation vulnerability in the Sandbox component of Avast Antivirus prior to… CVSS 3.1HIGH 8.8

See all 31 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences