Security readout for executives and security teams
Plain-English summary
CVE-2020-20118 is a local denial-of-service flaw in Avast AntiVirus before version 19.7. A person who already has local access to a machine could send a crafted request to Avast's aswSnx.sys driver and crash or disrupt protection or system stability.
Executive priority
Treat this as a targeted endpoint stability risk, not a confirmed internet-scale emergency. Remediate during normal endpoint maintenance unless affected systems are shared, sensitive, or operationally critical.
Technical view
The CVE describes a buffer overflow in the Avast AntiVirus aswSnx.sys driver, reachable through a crafted local request. Public metadata identifies the impact as denial of service, not remote compromise. The affected range is stated only as versions before 19.7.
Likely exposure
Exposure is most likely on Windows endpoints running Avast AntiVirus earlier than 19.7, especially shared systems or machines where untrusted users can obtain local access. The source bundle does not provide CPEs or a complete affected-product matrix.
Exploitation context
The available sources indicate local attacker access is required. CISA KEV is false in the supplied bundle, and no cited source supports active exploitation. A public researcher reference exists, but exploitation status and real-world prevalence are not established here.
Researcher notes
Evidence is sparse. The CVE record names a buffer overflow in aswSnx.sys and a local crafted request causing denial of service. No CVSS, CWE, CPE, vendor advisory, or active exploitation evidence is included in the supplied bundle.
Mitigation direction
- Upgrade Avast AntiVirus to version 19.7 or later where applicable.
- Check Avast vendor guidance for any newer advisories or replacement versions.
- Reduce local access for untrusted users on affected endpoints.
- Prioritize shared workstations, kiosks, and high-availability systems.
Validation and detection
- Inventory endpoints running Avast AntiVirus and record installed versions.
- Identify systems with Avast AntiVirus earlier than 19.7.
- Confirm whether aswSnx.sys is present and loaded on suspected endpoints.
- After remediation, verify Avast version is 19.7 or later.
- Document any systems where upgrade is blocked or unsupported.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CVE-2020-20118 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Unknown
- CVSS
- Not scored
- Known Exploited
- No
- Published
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
SSVC decision data
Vulnerability timeline
Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.
- CVE reservedCVE Program
The CVE ID was reserved by the assigning CNA.
- CVE publishedCVE Program
The CVE record was published.
- CVE updatedCVE Program
The CVE record metadata indicates this as the latest update time.
ADP provider summaries
Source materials
- CVE List V5 sourceCVE List V5
- https://gitlab.com/yongchuank/avast-aswsnx-ioctl-82ac0060-oob-writeCVE reference, mitre
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.