Security readout for executives and security teams
Plain-English summary
Backdrop CMS had a stored XSS issue in certain block descriptions. A user with permission to create custom blocks could craft content that runs script in an administrator’s browser while configuring a layout. The permission requirement limits exposure, but compromised or over-privileged accounts could still turn this into an administrative-session risk.
Executive priority
Treat this as a controlled but real CMS administrative risk. Prioritize upgrades for internet-facing Backdrop sites and environments with delegated content administration, but it is less urgent than unauthenticated remote code execution or known-exploited flaws.
Technical view
CVE-2019-19901 affects Backdrop CMS 1.13.x before 1.13.5 and 1.14.x before 1.14.2. The flaw is insufficient output filtering when displaying some administrator-created custom block descriptions, enabling cross-site scripting in the layout configuration workflow. The CVE record notes the attacker needs custom block creation permission.
Likely exposure
Exposure is limited to Backdrop CMS sites running the affected version ranges, especially where users beyond tightly trusted administrators can create custom blocks. The provided sources do not indicate anonymous exploitation or affected products beyond Backdrop CMS core.
Exploitation context
The source bundle does not report active exploitation, and the CVE is not marked as KEV. Exploitation requires a user with custom block creation permission to influence what an administrator later views in layout configuration.
Researcher notes
Evidence is limited to the CVE metadata and Backdrop advisory reference. No CVSS, CWE, exploit-in-the-wild evidence, or detailed patch mechanics are provided in the bundle, so validation should focus on version, permissions, and vendor advisory alignment.
Mitigation direction
- Upgrade Backdrop CMS 1.13.x to 1.13.5 or later, or 1.14.x to 1.14.2 or later.
- Restrict custom block creation permissions to trusted administrators only.
- Review the Backdrop advisory for any branch-specific guidance.
- Audit existing custom block descriptions for unexpected script-like content.
Validation and detection
- Inventory Backdrop CMS versions and identify any 1.13.x or 1.14.x deployments below fixed releases.
- Review roles allowed to create custom blocks.
- Confirm layout administrators no longer view unfiltered block descriptions after upgrading.
- Check recent custom block changes by privileged or delegated users.
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-2019-19901 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://backdropcms.org/security/backdrop-sa-core-2019-013CVE 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.