Security readout for executives and security teams
Plain-English summary
A malicious Webex recording file can compromise a user's computer if opened in Cisco Webex Player on Windows or macOS. The attacker must persuade the user to open the file, but successful exploitation can run code with that user's privileges.
Executive priority
Treat this as a high-priority endpoint hygiene issue for organizations using Webex recordings. The attack depends on user action, but the impact is full compromise of the targeted user's workstation context.
Technical view
CVE-2021-1526 is a CWE-119 memory corruption issue caused by insufficient validation of values in Webex Recording Format files. The CVSS 3.1 score is 7.8, with local attack vector, low complexity, no privileges required, and required user interaction.
Likely exposure
Exposure is most likely on Windows or macOS endpoints with Cisco Webex Player or Webex Meetings components capable of opening WRF files. The source bundle does not identify specific affected versions beyond Cisco Webex Meetings.
Exploitation context
The bundle does not report CISA KEV listing or active exploitation. Exploitation requires social engineering through a malicious WRF link or attachment and user opening the file locally with affected software.
Researcher notes
The key gaps are affected version granularity and explicit remediation details in the supplied bundle. Validation should focus on software inventory, WRF file handling, and Cisco advisory mapping rather than assuming a specific fixed version.
Mitigation direction
- Inventory Windows and macOS systems with Cisco Webex Player or Webex Meetings components installed.
- Review Cisco's advisory for affected versions and fixed software guidance.
- Apply Cisco-recommended updates or remove unused Webex Player components.
- Block or quarantine unexpected WRF attachments and links where email controls support it.
- Warn users not to open unsolicited Webex recording files from untrusted sources.
Validation and detection
- Confirm whether endpoints can open WRF files with Cisco Webex Player.
- Compare installed Webex software against Cisco's advisory guidance.
- Review email security logs for recent WRF attachments or suspicious Webex recording links.
- Check endpoint alerts for unusual child processes launched by Webex Player.
- Document systems where version or remediation status cannot be confirmed.
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-119: 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 lookupExecution 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 lookupCVE-2021-1526 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
- 7.8 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/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:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H1.85.9Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
7.8HighVector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Source materials
- CVE List V5 sourceCVE List V5
- 20210602 Cisco Webex Player Memory Corruption 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 Restriction of Operations within the Bounds of a Memory Buffer
Improper Restriction of Operations within the Bounds of a Memory Buffer represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.