Security readout for executives and security teams
Plain-English summary
Cisco Webex Player on Windows and macOS can mishandle specially crafted Webex Recording Format files. If a user opens a malicious WRF file, the player may crash and expose memory state information from the application. This is not described as a remote, automatic compromise.
Executive priority
Treat this as a moderate endpoint hygiene issue, not an emergency internet-facing exposure. Prioritize patching where Webex recording files are commonly exchanged, especially among executives, sales, support, and external-facing teams.
Technical view
CVE-2021-1527 is a CWE-119 memory corruption issue caused by insufficient validation of values inside WRF recording files. Exploitation requires local user interaction: the target must open a malicious WRF file delivered by link or attachment. CVSS 3.1 is 5.3, reflecting low-complexity local attack with limited confidentiality, integrity, and availability impact.
Likely exposure
Exposure is most likely on endpoints with Cisco Webex Player or Webex Meetings components able to open WRF files. Risk is higher for users who receive external meeting recordings by email or links and open them locally on Windows or macOS.
Exploitation context
The source bundle does not show CISA KEV listing or active exploitation. The described attack depends on social engineering and a user opening a malicious recording file. Impact is limited to the affected application context, including application termination and memory state information exposure.
Researcher notes
Evidence supports memory corruption through malformed WRF file parsing with required user interaction. The provided sources do not include exploit-in-the-wild evidence, detailed affected version ranges, or named fixed builds, so remediation should be tied directly to Cisco’s advisory.
Mitigation direction
- Check Cisco’s advisory for affected and fixed Webex Player releases.
- Update Cisco Webex Player or Webex Meetings components per vendor guidance.
- Limit opening WRF files from untrusted senders or external links.
- Educate users to treat unexpected recording attachments as suspicious.
- Use email filtering to flag or quarantine unexpected WRF attachments.
Validation and detection
- Inventory Windows and macOS endpoints with Cisco Webex Player installed.
- Confirm installed versions against Cisco’s affected and fixed release guidance.
- Review mail and download telemetry for unexpected WRF files.
- Check endpoint crash reports for Webex Player failures after opening WRF files.
- Verify user-facing file handling controls cover Webex recording attachments.
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
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CWE-119: Exact CWE lookup
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Open ATT&CK lookupCVE-2021-1527 mapping review
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Open ATT&CK lookup- Severity
- Medium
- CVSS
- 5.3 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:L
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:L/I:L/A:L1.83.4Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
5.3MediumVector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:L
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.