Security readout for executives and security teams
Plain-English summary
This flaw lets an outside attacker abuse a logged-in Cisco Unified Communications administrator’s browser if they can convince that user to open a malicious link. The attacker could then make changes as that user, including configuration changes or deleting user accounts. The prompt provides no evidence of active exploitation.
Executive priority
Treat this as a moderate-priority integrity risk for communications infrastructure. It is not reported as actively exploited in the provided sources, but a successful attack could alter system configuration through a privileged user’s session.
Technical view
CVE-2021-34773 is a CSRF weakness in the web-based management interface for Cisco Unified CM, Unified CM SME, and Unified CM IM&P. It is rated CVSS 6.5, requires user interaction, needs no attacker privileges, and primarily affects integrity. Confidentiality and availability impact are not identified in the provided CVSS vector.
Likely exposure
Exposure is most relevant where affected Cisco Unified Communications management interfaces are used by administrators or privileged operators. Risk increases if those users browse email or external sites while authenticated to the management interface. The provided bundle does not include affected version ranges.
Exploitation context
The attacker must persuade a user of the management interface to click a malicious link. Successful exploitation runs actions with that user’s privileges. The source bundle marks KEV as false and provides no cited evidence of active exploitation.
Researcher notes
The issue maps to CWE-352 with vector CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N. The prompt lacks fixed-version details and affected version ranges, so validation should be anchored to the Cisco advisory rather than assumptions.
Mitigation direction
- Review Cisco’s advisory for affected releases and fixed software guidance.
- Prioritize patching or upgrading affected Cisco Unified Communications products.
- Restrict management interface access to trusted administrative networks.
- Reduce administrator exposure to untrusted links while management sessions are active.
- Review account and configuration change controls for privileged users.
Validation and detection
- Inventory Cisco Unified CM, Unified CM SME, and Unified CM IM&P deployments.
- Compare product versions against Cisco’s advisory and current vendor guidance.
- Confirm management interfaces are not broadly reachable beyond administrative networks.
- Review recent configuration changes and deleted user accounts for anomalies.
- Verify remediation status in vulnerability management records.
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-352: User-session and phishing behavior lookup
Client-side and session-facing weaknesses should be reviewed alongside initial-access and user-execution behaviors. 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-2021-34773 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
- 6.5 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/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:N/UI:R/S:U/C:N/I:H/A:N2.83.6Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
6.5MediumVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N
Source materials
- CVE List V5 sourceCVE List V5
- 20211103 Cisco Unified Communications Products Cross-Site Request Forgery 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.
Cross-Site Request Forgery (CSRF)
Cross-Site Request Forgery (CSRF) represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.