CVE intelligence and bounded remediation

CVE-2024-23330 — Tuta is an encrypted email service

Medium CVSS 5.3

Tuta is an encrypted email service. In versions prior to 119.10, an attacker can attach an image in a html mail which is loaded from external resource in the default setting, which should prevent loading of external resources. When displaying emails containing external content, they should be loaded by default only after confirmation by the user. However, it could be recognized that certain embedded images (see PoC) are loaded, even though the "Automatic Reloading of Images" function is disabled by default. The reloading is also done unencrypted via HTTP and redirections are followed. This behavior is unexpected for the user, since the user assumes that external content will only be loaded after explicit manual confirmation. The loading of external content in e-mails represents a risk, because this makes the sender aware that the e-mail address is used, when the e-mail was read, which device is used and expose the user's IP address. Version 119.10 contains a patch for this issue.

Severity
Medium
CVSS
5.3 (3.1)
Published
2024-01-23
CISA KEV
Not currently listed
Ecosystem
software/application
Weaknesses
CWE-918

Affected products

  • tuta / tutanota

Matched remediation archetype

Server-side request forgery and unintended proxying

This catalog composition supplies bounded fallback guidance. Explicitly reviewed curated workflows load with the complete record below.

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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