Security readout for executives and security teams
Plain-English summary
This issue affects Invision Community before 4.6.5.1. An attacker could store malicious content through an uploaded file embedded in user content, potentially leading beyond browser script execution if administrator behavior and privileges align. The public bundle does not show active exploitation.
Executive priority
Treat as a high-priority remediation for externally exposed community sites, especially where untrusted users can upload content. The business concern is administrator compromise leading to deeper platform control, although public evidence here does not confirm active exploitation.
Technical view
CVE-2021-39250 is a stored XSS in Invision Community/IP-Board before 4.6.5.1 involving uploaded files placed in IFRAME elements inside user-generated content. The described RCE chain depends on administrator interaction, session exposure through Referer behavior, widget installation ability, and template editing privileges.
Likely exposure
Internet-facing community forums or portals running Invision Community, IPS Community Suite, or IP-Board before 4.6.5.1 are the likely exposure. Risk is higher where users can upload files or create rich user-generated content reviewed by administrators.
Exploitation context
The source bundle describes a stored XSS-to-RCE chain, but does not cite KEV listing or confirmed active exploitation. The chain appears conditional and administrator-dependent, so exposure validation should focus on affected version, upload permissions, iframe-capable content, and administrator workflows.
Researcher notes
Evidence is limited to the CVE description, SSD advisory reference, and Invision 4.6.5.1 release reference. No CVSS, CWE, KEV, or broad affected CPE data is provided in the bundle. Avoid assuming exploit prevalence or unsupported product variants.
Mitigation direction
- Upgrade affected Invision Community deployments to 4.6.5.1 or later.
- Review Invision release notes and vendor guidance for exact remediation requirements.
- Temporarily restrict untrusted file uploads until affected systems are updated.
- Review administrator sessions after suspected malicious content exposure.
- Audit recent user-generated content containing embedded uploaded files.
Validation and detection
- Inventory all Invision Community, IPS Community Suite, or IP-Board deployments.
- Confirm each deployment version is 4.6.5.1 or later.
- Check whether users can upload files into rich content areas.
- Review administrator activity around suspicious embedded content.
- Search logs for unusual administrative template or widget changes.
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.
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 lookupCVE-2021-39250 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://ssd-disclosure.com/ssd-advisory-ip-board-stored-xss-to-rce-chain/CVE reference · x_refsource_MISC
- https://invisioncommunity.com/release-notes/4651-r102/CVE 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.