Security readout for executives and security teams
Plain-English summary
CVE-2019-5020 is a denial-of-service flaw in Yara 3.8.1. A malicious binary file can cause Yara to hit an assertion failure during object lookup and crash. The main business risk is disruption to malware scanning, triage, or security automation that relies on this Yara version.
Executive priority
Treat this as a moderate operational risk. It does not expose data or enable code execution in the provided evidence, but it can disrupt security scanning services that depend on vulnerable Yara processing.
Technical view
The source describes CWE-617 in Yara 3.8.1 object lookup. A specially crafted binary can make a negative value satisfy an assert, causing denial of service. CVSS 3.0 is 6.5 with no confidentiality or integrity impact and high availability impact.
Likely exposure
Exposure is most likely where Yara 3.8.1 processes untrusted binaries, such as malware analysis, file intake, detection engineering, or automated scanning workflows. The supplied evidence identifies Yara 3.8.1 only.
Exploitation context
The CVE says an attacker can create a malicious binary to trigger the issue. CISA KEV is false in the provided bundle, and no cited source here supports active exploitation in the wild.
Researcher notes
Evidence is limited to public CVE data and the Talos report reference. The key research focus is object lookup assertion handling in Yara 3.8.1 and availability impact when parsing crafted binaries. Do not infer broader affected versions without vendor evidence.
Mitigation direction
- Inventory Yara usage and prioritize systems running Yara 3.8.1.
- Check Yara or Talos guidance for a supported fixed release or workaround.
- Isolate scanning workers that process untrusted binaries.
- Add process supervision so scanner crashes do not halt dependent workflows.
- Limit high-availability workflows from relying on a single vulnerable scanner.
Validation and detection
- Confirm whether any deployed Yara instance is version 3.8.1.
- Map where Yara processes externally supplied binary files.
- Review scanner logs for assertion failures or unexplained Yara process crashes.
- Verify vendor guidance before approving remediation steps.
- Retest availability of scanning pipelines after remediation.
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.
CWE-617: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCVE-2019-5020 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
- Medium
- CVSS
- 6.5 (3.0)
- Known Exploited
- No
- Published
Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
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.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H2.83.6Primary CVE scoreVulnerability scoring details
Base CVSS 3.0 score
6.5MediumVector: CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
Source materials
- CVE List V5 sourceCVE List V5
- https://talosintelligence.com/vulnerability_reports/TALOS-2019-0781CVE reference · x_refsource_MISC
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.
Reachable Assertion
Reachable Assertion represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.