Security readout for executives and security teams
Plain-English summary
CVE-2020-17398 is a local information disclosure flaw in Parallels Desktop 15.1.4. It matters most on Macs where an attacker already has low-privileged code execution. By itself it is not a remote break-in, but the source says it could support a broader chain toward kernel-level code execution.
Executive priority
Treat this as a targeted workstation risk, not an internet-wide emergency. Remediate affected Parallels Desktop 15.1.4 systems as part of endpoint hardening, with higher urgency where users handle sensitive data or have administrative access.
Technical view
The flaw is in the prl_hypervisor kernel extension. Missing validation of user-supplied data can cause an out-of-bounds buffer read, mapped to CWE-129. CVSS 3.0 is 6.5 with local attack vector, low privileges required, no user interaction, changed scope, and high confidentiality impact.
Likely exposure
Exposure appears limited to affected Parallels Desktop 15.1.4 installations, especially developer, IT, or administrative macOS workstations running virtual machines. The bundle does not identify other affected Parallels versions or products.
Exploitation context
The CVE is not listed as KEV in the bundle. The provided description requires prior low-privileged local code execution. It also states the issue can be chained with other vulnerabilities for kernel-context arbitrary code execution, but the bundle does not establish active exploitation.
Researcher notes
Evidence supports a local out-of-bounds read in prl_hypervisor with high confidentiality impact and possible chain value. The source bundle does not provide exploit details, fixed version specifics, or active exploitation evidence, so validation should stay inventory- and vendor-guidance-based.
Mitigation direction
- Inventory macOS hosts for Parallels Desktop 15.1.4.
- Check Parallels KB 125013 for vendor-supported remediation guidance.
- Prioritize remediation on privileged user, developer, and IT workstations.
- Restrict untrusted local code execution on affected Macs.
- Monitor for suspicious local process activity around virtualization components.
Validation and detection
- Confirm installed Parallels Desktop versions across managed macOS endpoints.
- Identify hosts loading the prl_hypervisor kernel extension.
- Verify remediation status against Parallels vendor guidance, not assumptions.
- Review endpoint telemetry for unexpected local execution by low-privileged users.
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-129: 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 lookupExecution behavior lookup
The CVE wording references code or command execution, so execution technique review may help defensive triage. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2020-17398 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:L/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N
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:L/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N24Primary CVE scoreVulnerability scoring details
Base CVSS 3.0 score
6.5MediumVector: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N
Source materials
- CVE List V5 sourceCVE List V5
- https://kb.parallels.com/en/125013CVE reference · x_refsource_MISC
- https://www.zerodayinitiative.com/advisories/ZDI-20-1016/CVE 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.
Improper Validation of Array Index
Improper Validation of Array Index represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.