LiveActive security incident?Get immediate response
CVE Record

CVE-2021-1536: Cisco Webex Meetings, Webex Network Recording Player, and Webex Teams DLL Injection Vulnerability

A vulnerability in Cisco Webex Meetings Desktop App for Windows, Cisco Webex Meetings Server, Cisco Webex Network Recording Player for Windows, and Cisco Webex Teams for Windows could allow an authenticated, local attacker to perform a DLL injection attack on an affected device. To exploit this vulnerability, the attacker must have valid credentials on the Windows system. This vulnerability is due to incorrect handling of directory paths at run time. An attacker could exploit this vulnerability by inserting a configuration file in a specific path in the system, which can cause a malicious DLL file to be loaded when the application starts. A successful exploit could allow the attacker to execute arbitrary code on the affected system with the privileges of another user account.

MediumCVSS 4.8Not KEV-listedUpdated
Glexia's TakeAutomated analysismoderate

Security readout for executives and security teams

Plain-English summary

This is a local Windows vulnerability in several Cisco Webex components. A logged-in attacker could influence how Webex loads files at startup so malicious code runs under another user’s privileges. It is not described as remotely exploitable, and the bundle does not show active exploitation.

Executive priority

Treat this as a moderate endpoint hardening and patch-management item. It is not presented as an internet-facing emergency, but it can help an attacker with local access escalate impact on important user systems.

Technical view

CVE-2021-1536 is a CWE-427 DLL injection issue caused by incorrect runtime directory path handling. Exploitation requires local Windows credentials and user interaction per CVSS. A crafted configuration file in a relevant path can cause Webex to load a malicious DLL when the application starts.

Likely exposure

Exposure is most likely on Windows endpoints or servers running Cisco Webex Meetings Desktop App, Webex Meetings Server, Webex Network Recording Player, or Webex Teams. The supplied affected-version detail is incomplete, so teams must verify exact exposure against Cisco’s advisory.

Exploitation context

The source bundle does not indicate CISA KEV listing or active exploitation. Practical exploitation requires local authenticated access to the Windows system, making this more relevant for insider risk, compromised user accounts, shared workstations, or attacker foothold expansion.

Researcher notes

The key constraint is local authenticated access. The important research focus is path-handling behavior and DLL search/loading control, not remote entry. The public bundle lacks fixed-version detail, so validation should be tied directly to Cisco’s advisory.

Mitigation direction

  • Review Cisco’s advisory for affected and fixed software versions.
  • Update or replace affected Cisco Webex Windows components per vendor guidance.
  • Limit local Windows account access on shared or high-value systems.
  • Harden endpoint controls against unauthorized DLL and configuration file placement.
  • Prioritize systems used by administrators or privileged business users.

Validation and detection

  • Inventory Cisco Webex Windows components across endpoints and servers.
  • Compare installed versions with Cisco’s advisory and asset records.
  • Review endpoint telemetry for unexpected Webex-related DLL loading behavior.
  • Check for suspicious configuration files in Webex-related runtime locations.
  • Confirm remediation through version reporting after updates.
Prepared
Confidence
medium
Sources
3

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

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 · low confidence lookup

CWE-427: 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 lookup
description · low confidence lookup

Execution behavior lookup

The CVE wording references code or command execution, so execution technique review may help defensive triage. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.

Open ATT&CK lookup
cve · low confidence lookup

CVE-2021-1536 mapping review

Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.

Open ATT&CK lookup
Vulnerability profileCVE Program record
Severity
Medium
CVSS
4.8 (3.1)
Known Exploited
No
Published

Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:L/I:L/A:L

Official CVE source material

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.

1CVSS vectors
0Timeline events
0ADP providers
2Source links

CVSS vector scores

1 official score

We 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.

ScoreVersionSeverityVectorExploitImpactSource
4.8CVSS 3.1MediumCVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:L/I:L/A:L1.33.4Primary CVE score

Vulnerability scoring details

Base CVSS 3.1 score

4.8Medium
CVSS 3.1 vector shape for CVE-2021-1536Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:L/I:L/A:L

Attack Vector
NetworkAdjacentLocalPhysical
Attack Complexity
LowHigh
Privileges Required
NoneLowHigh
User Interaction
NoneRequired
Scope
ChangedUnchanged
Confidentiality Impact
HighLowNone
Integrity Impact
HighLowNone
Availability Impact
HighLowNone
Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
CiscoCisco Webex Teamsn/aListed
Weakness

CWE details

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.

CWE-427 · source CWE mapping

Uncontrolled Search Path Element

Uncontrolled Search Path Element represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.