Security readout for executives and security teams
Plain-English summary
This issue lets a logged-in attacker place their chosen hyperlink into a Webex meeting invitation email. The email comes from a trusted Webex source, which can make phishing or misdirection more convincing. It does not indicate system takeover, data theft, or service disruption by itself.
Executive priority
Treat this as a phishing-enablement risk rather than a direct infrastructure compromise. Prioritize remediation for environments where many users can generate Webex invitations or where trusted meeting emails routinely reach executives, customers, or partners.
Technical view
CVE-2021-1221 is a Cisco Webex Meetings and Webex Meetings Server UI input-validation flaw, mapped to CWE-20. An authenticated remote user can enter a URL into a UI field, causing generated meeting invitations to include an attacker-chosen link. CVSS 3.1 score is 4.1 with low privileges and user interaction required.
Likely exposure
Exposure is most relevant where users can create Webex meetings or invitations through affected Cisco Webex Meetings or Webex Meetings Server software. The source bundle does not provide specific affected version ranges.
Exploitation context
The CVE is not listed as KEV in the provided bundle, and no source here claims active exploitation. Abuse requires authenticated access to the Webex UI and a recipient choosing to click the injected invitation link.
Researcher notes
Key constraints are authenticated attacker, UI injection path, user interaction, and integrity-only impact. The provided evidence does not include affected version detail, exploit activity, or patch specifics beyond the Cisco advisory reference.
Mitigation direction
- Review Cisco advisory for affected releases and official fixed-version guidance.
- Apply Cisco-provided updates or mitigations where the deployment is affected.
- Restrict meeting-creation privileges to users with a business need.
- Warn users to verify unexpected Webex invitation links before opening them.
- Use email security controls to flag suspicious external destinations in trusted invitations.
Validation and detection
- Inventory Cisco Webex Meetings Server and Webex Meetings usage in the organization.
- Compare deployed versions and service configuration against the Cisco advisory.
- Review who can create meetings and generate invitations.
- Check mail logs for Webex invitations containing unusual or unapproved destinations.
- Confirm user-awareness guidance covers trusted-source link manipulation.
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-20: 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-2021-1221 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
- 4.1 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:N/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:L/PR:L/UI:R/S:C/C:N/I:L/A:N2.31.4Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
4.1MediumVector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:N/I:L/A:N
Source materials
- CVE List V5 sourceCVE List V5
- 20210203 Cisco Webex Meetings and Cisco Webex Meetings Server Software Hyperlink Injection VulnerabilityCVE reference · vendor-advisory, x_refsource_CISCO
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 Input Validation
Improper Input Validation represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.