Security readout for executives and security teams
Plain-English summary
HCL Sametime 11.6 has a file transfer service flaw where a user session identifier can be altered. An authenticated user could upload files arbitrarily or delete directories, potentially disrupting service availability. The provided sources do not show active exploitation.
Executive priority
Prioritize this as a high-risk product remediation item if Sametime 11.6 is deployed. It is not supported by the provided evidence as an active exploitation emergency, but the availability impact can affect collaboration services.
Technical view
The vulnerability involves Sametime’s SID value, stored in a user cookie and reused for chat, notifications, and file transfers. Improper handling can enable arbitrary file upload and directory deletion. The CVE maps to CWE-22 and CWE-434 with CVSS 8.2, requiring low privileges and user interaction.
Likely exposure
Exposure is limited by the provided evidence to HCL Sametime version 11.6. Organizations running that version, especially with file transfer functionality available to authenticated users, should treat it as in scope. The sources do not identify other affected versions or deployment conditions.
Exploitation context
The source bundle does not show CISA KEV listing or cited active exploitation. CVSS indicates network reachability, low privileges, and required user interaction. The highest business concern is denial of service from directory deletion, with lower confidentiality and integrity impacts also noted.
Researcher notes
Evidence is sparse beyond the CVE description and HCL reference. Do not assume additional affected versions, public exploit availability, or a specific patch level without the vendor advisory. Focus validation on SID handling, file transfer exposure, and observed file operation anomalies.
Mitigation direction
- Review HCL advisory KB0097430 for vendor-confirmed fixes or workarounds.
- Inventory HCL Sametime deployments and identify any version 11.6 systems.
- Apply vendor-provided updates or mitigations when confirmed by HCL guidance.
- Restrict Sametime access to trusted users and networks where operationally feasible.
- Monitor Sametime file transfer activity for unexpected uploads or deletion behavior.
Validation and detection
- Confirm whether HCL Sametime 11.6 is present in production or legacy environments.
- Check whether Sametime file transfer functionality is enabled and reachable.
- Compare installed builds against HCL advisory KB0097430 guidance.
- Review logs for unusual file transfer, upload, or directory deletion events.
- Verify compensating access controls around authenticated Sametime users.
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-22: File access and web shell behavior lookup
File traversal and upload weaknesses can lead teams to review file, web shell, execution, and collection telemetry. 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 lookupCWE-434: File access and web shell behavior lookup
File traversal and upload weaknesses can lead teams to review file, web shell, execution, and collection telemetry. 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 lookupFile access behavior lookup
The CVE wording references file access or upload behavior, so file telemetry and web shell review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2021-27771 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
- 8.2 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/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:L/UI:R/S:C/C:L/I:L/A:H2.35.3Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
8.2HighVector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:H
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.
Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.
Unrestricted Upload of File with Dangerous Type
Unrestricted Upload of File with Dangerous Type represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.