Security readout for executives and security teams
Plain-English summary
CVE-2021-34986 is a local privilege escalation issue in Parallels Desktop 16.5.0 (49183). A user or malware already running with low privileges on the Mac could abuse Parallels Service behavior to run code as root, turning an endpoint foothold into full system control.
Executive priority
Treat this as a high-priority endpoint hardening issue where Parallels Desktop 16.5.0 is present. It is not described as remotely exploitable, but it can materially increase the impact of malware or a compromised local account.
Technical view
The flaw is in Parallels Service and is associated with CWE-367. The CVE describes symbolic-link abuse that lets a local, low-privileged attacker cause a file to execute in the root context. CVSS 3.0 is 7.8 with local access, low complexity, low privileges, and no user interaction.
Likely exposure
Exposure is limited to systems running Parallels Desktop 16.5.0 (49183). Highest concern is developer or administrative Mac workstations where Parallels is installed and an attacker could first gain low-privileged local code execution.
Exploitation context
The source bundle does not show CISA KEV listing or cited evidence of active exploitation. Exploitation requires prior local code execution, but successful exploitation could provide root-level arbitrary code execution on the affected host.
Researcher notes
Evidence is specific to Parallels Desktop 16.5.0 (49183). Do not generalize to other versions without vendor confirmation. The key validation question is whether the vulnerable Parallels Service build exists on a host that an attacker could already run local code on.
Mitigation direction
- Inventory Macs for Parallels Desktop 16.5.0 (49183).
- Check Parallels vendor guidance for fixed versions or supported remediation.
- Upgrade, remove, or isolate affected Parallels Desktop installations.
- Limit local code execution paths on developer and shared workstations.
- Monitor endpoints for suspicious privilege escalation behavior.
Validation and detection
- Confirm installed Parallels Desktop version on managed Macs.
- Identify users or processes able to execute local low-privileged code.
- Review endpoint telemetry for unexpected root process creation by Parallels components.
- Verify remediation by confirming affected version is no longer present.
- Track vendor advisory status before closing the finding.
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-367: 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-2021-34986 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
- 7.8 (3.0)
- Known Exploited
- No
- Published
Vector: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/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:U/C:H/I:H/A:H1.85.9Primary CVE scoreVulnerability scoring details
Base CVSS 3.0 score
7.8HighVector: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/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-22-385/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.
Time-of-check Time-of-use (TOCTOU) Race Condition
Time-of-check Time-of-use (TOCTOU) Race Condition represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.