Security readout for executives and security teams
Plain-English summary
HCL Sametime 11.6 is reported vulnerable to clickjacking in meeting chat. A user could be tricked into clicking a misleading interface, causing limited confidentiality or integrity impact. The score is medium because exploitation needs user interaction and high attack complexity, with no availability impact reported.
Executive priority
Treat as a moderate-priority collaboration-platform issue. It does not indicate direct server takeover, but it can affect user trust and chat confidentiality or integrity. Prioritize vendor review and remediation, especially for externally reachable or broadly used Sametime deployments.
Technical view
CVE-2021-27773 is a CWE-451 user-interface misrepresentation issue in HCL Sametime 11.6 meeting chat. CVSS 3.1 is 4.2: network attack vector, high complexity, no privileges required, user interaction required, unchanged scope, low confidentiality and integrity impact, no availability impact.
Likely exposure
Exposure is likely limited to organizations running HCL Sametime 11.6, particularly deployments where meeting chat is reachable by users who may follow attacker-controlled links or embedded content. The source bundle does not identify other affected versions or products.
Exploitation context
The source bundle does not show active exploitation, and the CVE is not listed as KEV. Exploitation requires user interaction and a successful clickjacking setup, so it is more plausible in phishing or social-engineering scenarios than automated compromise.
Researcher notes
Evidence is sparse beyond the CVE metadata and HCL reference. Do not assume broader version impact, active exploitation, or a specific fix without the vendor article. The key technical clue is CWE-451 with clickjacking in the meeting chat context.
Mitigation direction
- Identify whether HCL Sametime 11.6 is deployed.
- Review the HCL advisory for fixed versions or vendor mitigations.
- Apply HCL-provided updates or configuration changes when available.
- Reduce exposure of meeting services to untrusted users where feasible.
- Educate users about suspicious meeting links and embedded content.
Validation and detection
- Confirm installed Sametime versions against the affected 11.6 listing.
- Check whether HCL advisory guidance has been applied.
- Review web security headers and framing protections for Sametime pages.
- Test meeting chat workflows only in authorized environments.
- Monitor helpdesk or security reports for suspicious meeting-link activity.
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-451: 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-2021-27773 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
- 4.2 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/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:N/AC:H/PR:N/UI:R/S:U/C:L/I:L/A:N1.62.5Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
4.2MediumVector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:L/A:N
Source materials
- CVE List V5 sourceCVE List V5
- https://support.hcltechsw.com/csm?id=kb_article&sysparm_article=KB0097430CVE 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.
User Interface (UI) Misrepresentation of Critical Information
User Interface (UI) Misrepresentation of Critical Information represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.