Security readout for executives and security teams
Plain-English summary
CVE-2021-39985 is a Huawei HarmonyOS 2.0 issue in the HwNearbyMain module. A network attacker may be able to trigger a process restart, creating an availability risk. The public record does not show data theft, data modification, or confirmed active exploitation.
Executive priority
Treat this as a high-priority availability issue for HarmonyOS 2.0 environments. It does not currently indicate data compromise, but unauthenticated network reachability and possible process restarts justify prompt inventory and vendor update checks.
Technical view
The issue is CWE-129, improper validation of an array index, in Huawei HarmonyOS 2.0 HwNearbyMain. CVSS 3.1 is 7.5: network reachable, low complexity, no privileges, no user interaction, unchanged scope, and high availability impact only.
Likely exposure
Exposure appears limited to Huawei HarmonyOS 2.0 systems with the HwNearbyMain module. The provided sources do not identify other Huawei products, device models, or versions as affected.
Exploitation context
The CVE is not listed as KEV in the provided bundle, and no cited source confirms active exploitation. Public evidence supports availability impact through process restart, not confidentiality or integrity compromise.
Researcher notes
The public detail is sparse. The core facts are CWE-129 in HwNearbyMain, HarmonyOS 2.0 affected, and process restart impact. Do not assume broader product exposure, exploit availability, or a specific patch beyond Huawei's advisory.
Mitigation direction
- Review Huawei's November 2021 HarmonyOS security bulletin for official remediation guidance.
- Inventory Huawei devices running HarmonyOS 2.0.
- Apply Huawei-provided updates if available for the affected device model.
- Prioritize devices where process restarts could disrupt business operations.
- Monitor affected devices for unexpected service or process restarts.
Validation and detection
- Confirm whether managed devices run Huawei HarmonyOS 2.0.
- Check whether HwNearbyMain is present on in-scope devices.
- Compare device patch levels against Huawei's referenced security bulletin.
- Review operational logs for unexplained process restarts.
- Record unsupported or unpatched devices for risk acceptance or replacement planning.
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-2021-39985 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
- 7.5 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/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:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H3.93.6Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
7.5HighVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Source materials
- CVE List V5 sourceCVE List V5
- https://device.harmonyos.com/en/docs/security/update/security-bulletins-202111-0000001217889667CVE 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.