CVE intelligence and bounded remediation

CVE-2018-12243 — Symantec Messaging Gateway security vulnerability

High CVSS 8.8

The Symantec Messaging Gateway product prior to 10.6.6 may be susceptible to a XML external entity (XXE) exploit, which is a type of issue where XML input containing a reference to an external entity is processed by a weakly configured XML parser. The attack uses file URI schemes or relative paths in the system identifier to access files that should not normally be accessible.

Severity
High
CVSS
8.8 (3.0)
Published
2018-09-19
CISA KEV
Not currently listed
Ecosystem
software/application
Weaknesses
CWE-611

Affected products

  • symantec / messaging_gateway

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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