CVE intelligence and bounded remediation

CVE-2023-23926 — APOC (Awesome Procedures on Cypher) is an add-on library for Neo4j

High CVSS 8.1

APOC (Awesome Procedures on Cypher) is an add-on library for Neo4j. An XML External Entity (XXE) vulnerability found in the apoc.import.graphml procedure of APOC core plugin prior to version 5.5.0 and 4.4.0.14 (4.4 branch) in Neo4j graph database. XML External Entity (XXE) injection occurs when the XML parser allows external entities to be resolved. The XML parser used by the apoc.import.graphml procedure was not configured in a secure way and therefore allowed this. External entities can be used to read local files, send HTTP requests, and perform denial-of-service attacks on the application. Abusing the XXE vulnerability enabled assessors to read local files remotely. Although with the level of privileges assessors had this was limited to one-line files. With the ability to write to the database, any file could have been read. Additionally, assessors noted, with local testing, the server could be crashed by passing in improperly formatted XML. The minimum version containing a patch for this vulnerability is 5.5.0. Those who cannot upgrade the library can control the allowlist of the procedures that can be used in your system.

Severity
High
CVSS
8.1 (3.1)
Published
2023-02-16
CISA KEV
Not currently listed
Ecosystem
software/application
Weaknesses
CWE-611

Affected products

  • neo4j / awesome_procedures_on_cyper

Matched remediation archetype

XML external entity and unsafe XML processing

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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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