Security readout for executives and security teams
Plain-English summary
CVE-2020-17399 is a local privilege escalation flaw in Parallels Desktop 15.1.4. An attacker already able to run low-privileged code on a Mac could potentially gain kernel-level control. This is serious for managed workstations, especially developer or admin laptops using Parallels.
Executive priority
Treat as a high-priority endpoint remediation issue, not an internet-edge emergency. It can convert an initial workstation foothold into kernel-level control, raising business risk on laptops with privileged access or sensitive data.
Technical view
The flaw is in the Parallels prl_hypervisor kernel extension. The source describes insufficient validation of user-supplied data, classified as CWE-129, causing a write past an allocated buffer. Successful exploitation may execute code in kernel context. CVSS is 8.8 with local attack vector and low privileges required.
Likely exposure
Exposure is limited to systems running Parallels Desktop 15.1.4. The attacker needs local code execution first, so this is not described as remotely reachable by the supplied sources. Highest concern is endpoints where Parallels runs on sensitive user workstations.
Exploitation context
The sources support local privilege escalation with low attack complexity, low privileges required, and no user interaction. The CVE is not listed as KEV in the supplied bundle, and no cited source here confirms active exploitation.
Researcher notes
Evidence identifies Parallels Desktop 15.1.4 and the prl_hypervisor kext. The available bundle does not provide exploit details or a named patched version. Validation should focus on asset inventory, kernel extension presence, and vendor advisory comparison.
Mitigation direction
- Check Parallels vendor guidance for the applicable fixed version or remediation.
- Upgrade or remove affected Parallels Desktop 15.1.4 installations.
- Restrict Parallels Desktop use to managed, patched endpoints.
- Reduce local code execution risk through endpoint controls and least privilege.
- Prioritize remediation on administrator, developer, and security-sensitive workstations.
Validation and detection
- Inventory endpoints for Parallels Desktop 15.1.4 installations.
- Confirm whether the prl_hypervisor kernel extension is present on affected Macs.
- Compare installed versions against Parallels KB guidance.
- Review EDR telemetry for unusual local privilege escalation behavior on affected hosts.
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 lookupCVE-2020-17399 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
- High
- CVSS
- 8.8 (3.0)
- Known Exploited
- No
- Published
Vector: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/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:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H26Primary CVE scoreVulnerability scoring details
Base CVSS 3.0 score
8.8HighVector: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
Source materials
- CVE List V5 sourceCVE List V5
- https://kb.parallels.com/en/125013CVE reference · x_refsource_MISC
- https://www.zerodayinitiative.com/advisories/ZDI-20-1017/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.