Security readout for executives and security teams
Plain-English summary
FusionPBX 4.5.7 is reported to allow cross-site scripting through an unsanitized query_string value in the device import page. A successful attack could make a victim's browser run attacker-supplied script in the FusionPBX web interface. The sources do not provide CVSS scoring, confirmed exploitation, or a named fixed release.
Executive priority
Treat this as a targeted web application hardening item, especially for internet-reachable PBX administration. Prioritize inventory and patch verification, but do not escalate as actively exploited based on the provided evidence.
Technical view
CVE-2020-21053 describes XSS in app/devices/device_imports.php where query_string was not sanitized before use. The public references include a disclosure blog and a FusionPBX commit. Available data does not identify CPEs, CWE mapping, exploit maturity, or a fixed version beyond the referenced code change.
Likely exposure
Exposure is most likely where FusionPBX 4.5.7 is deployed and the device import page is reachable by users or attackers able to influence requests. The source bundle does not establish whether other versions are affected.
Exploitation context
No CISA KEV listing or cited source in the bundle confirms active exploitation. The issue is remotely triggerable according to the CVE description, but the bundle does not provide attack prerequisites, authentication context, or real-world exploitation evidence.
Researcher notes
The CVE metadata is sparse: no CVSS, CWE, CPE, affected matrix, or fixed release is supplied. Analysis should anchor on FusionPBX 4.5.7, device_imports.php, query_string handling, and the referenced commit only.
Mitigation direction
- Inventory FusionPBX deployments and identify any running 4.5.7.
- Review and apply FusionPBX vendor guidance or the referenced upstream fix commit.
- Restrict FusionPBX administrative interfaces to trusted networks and users.
- Monitor for suspicious activity around the device import page.
Validation and detection
- Confirm whether app/devices/device_imports.php includes the referenced upstream change.
- Review query_string handling for sanitization and output encoding.
- Verify only intended administrators can access device import functionality.
- Check application logs for unusual requests involving device_imports.php.
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.
CVE-2020-21053 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
- Unknown
- CVSS
- Not scored
- Known Exploited
- No
- Published
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 and timeline data
No CVSS vectors or timeline events were available in the normalized CVE source material.
Source materials
- CVE List V5 sourceCVE List V5
- https://resp3ctblog.wordpress.com/2019/10/28/fusionpbx-xss-22/CVE reference · x_refsource_MISC
- https://github.com/fusionpbx/fusionpbx/commit/2ce613f1e9fe8ffab7a4cb9d1384444622285335CVE reference · x_refsource_MISC
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.