Security readout for executives and security teams
Plain-English summary
HCL BigFix Client installers in affected platform releases used a vulnerable InstallShield component. A local, low-privileged user could potentially gain higher privileges if the vulnerable installer path is present and user interaction occurs. This is a medium-risk endpoint management issue, not a remote internet-facing flaw based on the provided sources.
Executive priority
Treat as a scheduled remediation priority for endpoint management infrastructure. It is not described as remotely exploitable or actively exploited, but BigFix has broad endpoint reach, so stale installers should be removed quickly.
Technical view
CVE-2021-27766 is a local privilege escalation in HCL BigFix Platform Client installers due to the underlying InstallShield CVE-2021-41526 issue. Affected releases are BigFix Platform 9.5 through 9.5.18 and 10 through 10.0.5. CVSS 3.1 is 6.7 with local access, low complexity, low privileges, and required user interaction.
Likely exposure
Organizations are exposed where affected BigFix Client installers or affected platform releases remain deployed, stored, or used for endpoint installation. Exposure is mainly on managed endpoints or software distribution locations, not public services.
Exploitation context
The source bundle does not report active exploitation, and KEV is false. Exploitation requires local access, low privileges, and user interaction, which lowers broad attack likelihood but matters on shared endpoints or environments where installer packages are reused.
Researcher notes
The key dependency is InstallShield CVE-2021-41526 as incorporated into BigFix Client installers. The provided sources do not include exploit status, detailed attack procedure, or exact fixed build numbers beyond affected version ranges.
Mitigation direction
- Upgrade BigFix Platform and Client components outside the affected ranges per HCL guidance.
- Remove vulnerable BigFix Client installers from deployment shares and software portals.
- Check HCL advisory KB0098116 for fixed release guidance before rollout.
- Limit local user access to installer locations until remediation is complete.
Validation and detection
- Inventory BigFix Platform and Client versions across managed endpoints.
- Identify stored BigFix Client installers created from affected releases.
- Confirm deployed versions are not 9.5 through 9.5.18 or 10 through 10.0.5.
- Review endpoint records for unexpected privilege changes around installer execution.
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-269: Authorization and privilege behavior lookup
Authorization weaknesses can support privilege escalation and valid-account review, depending on exploit path. 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 lookupPrivilege behavior lookup
The CVE wording references privilege impact, so privilege escalation and authorization behavior review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2021-27766 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
- 6.7 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:C/C:H/I:L/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:3.1/AV:L/AC:L/PR:L/UI:R/S:C/C:H/I:L/A:N1.54.7Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
6.7MediumVector: CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:C/C:H/I:L/A:N
Source materials
- CVE List V5 sourceCVE List V5
- https://support.hcltechsw.com/csm?id=kb_article&sysparm_article=KB0098116CVE reference · x_refsource_MISC
- https://github.com/mandiant/Vulnerability-Disclosures/blob/master/2022/MNDT-2022-0024/MNDT-2022-0024.mdCVE 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 Privilege Management
Improper Privilege Management represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.