CVE intelligence and bounded remediation
CVE-2021-3902 — Dompdf Project Dompdf security vulnerability
An improper restriction of external entities (XXE) vulnerability in dompdf/dompdf's SVG parser allows for Server-Side Request Forgery (SSRF) and deserialization attacks. This issue affects all versions prior to 2.0.0. The vulnerability can be exploited even if the isRemoteEnabled option is set to false. It allows attackers to perform SSRF, disclose internal image files, and cause PHAR deserialization attacks.
- Severity
- Critical
- CVSS
- 9.8 (3.1)
- Published
- 2024-11-15
- CISA KEV
- Not currently listed
- Ecosystem
- software/application
- Weaknesses
- CWE-611
Affected products
- dompdf_project / dompdf
Matched remediation archetype
XML external entity and unsafe XML processing
This catalog composition supplies bounded fallback guidance. Explicitly reviewed curated workflows load with the complete record below.
Check exposure
- Inventory XML parsers used by APIs, file imports, office or image formats, identity protocols, feeds, and background jobs.
- Determine whether document type declarations, external entities, XInclude, schemas, or network resolvers are enabled.
- Map parser filesystem and network access and the sensitivity of documents it processes.
Remediate safely
- Configure each parser to reject document type declarations and disable external entity, XInclude, and network resolution features.
- Prefer a data format or hardened parser that does not support external resolution, and apply input size and depth limits.
- Update affected XML libraries and centralize secure parser construction so callers cannot silently override it.
Authoritative sources
Complete CVE record and remediation plan
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