CVE intelligence and bounded remediation

CVE-2023-26435 — It was possible to call filesystem and network references using the local LibreOffice instance using manipulated ODT documents

Medium CVSS 5

It was possible to call filesystem and network references using the local LibreOffice instance using manipulated ODT documents. Attackers could discover restricted network topology and services as well as including local files with read permissions of the open-xchange system user. This was limited to specific file-types, like images. We have improved existing content filters and validators to avoid including any local resources. No publicly available exploits are known.

Severity
Medium
CVSS
5 (3.1)
Published
2023-06-20
CISA KEV
Not currently listed
Ecosystem
software/application
Weaknesses
CWE-918

Affected products

  • open-xchange / open-xchange_appsuite_backend
  • open-xchange / open-xchange_appsuite_backend / 7.10.6

Showing 2 representative product identities from 3 source matches. Confirm exact affected versions with the linked vendor and NVD evidence.

Matched remediation archetype

Server-side request forgery and unintended proxying

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Check exposure

  • Inventory server-side URL fetchers, webhooks, importers, previews, redirects, proxies, and protocol handlers reachable from untrusted input.
  • Map egress paths to internal services, metadata endpoints, loopback, private address space, and privileged control planes.
  • Review DNS resolution, redirect, proxy, credential-forwarding, and URL parsing behavior without requesting sensitive targets.

Remediate safely

  • Replace arbitrary destinations with named integrations or a strict allowlist of schemes, hosts, ports, and paths.
  • Resolve and validate every destination and redirect hop, then enforce egress policy independently of application checks.
  • Remove ambient credentials and sensitive headers from fetchers; apply response size, time, and content limits.

Authoritative sources

Complete CVE record and remediation plan

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