CVE-2025-43857 (High) detected in net-imap-0.5.6.gem

[mend-bolt-for-github[bot]]

CVE-2025-43857 - High Severity Vulnerability

Vulnerable Library - net-imap-0.5.6.gem

Ruby client api for Internet Message Access Protocol

Library home page: https://rubygems.org/gems/net-imap-0.5.6.gem

Path to dependency file: /Gemfile.lock

Path to vulnerable library: /vendor/cache/net-imap-0.5.6.gem

Dependency Hierarchy:

• rails-7.0.8.7.gem (Root Library)
  • actionmailbox-7.0.8.7.gem
    • :x: net-imap-0.5.6.gem (Vulnerable Library)

Found in base branch: master

Vulnerability Details

Net::IMAP implements Internet Message Access Protocol (IMAP) client functionality in Ruby. Prior to versions 0.5.7, 0.4.20, 0.3.9, and 0.2.5, there is a possibility for denial of service by memory exhaustion when net-imap reads server responses. At any time while the client is connected, a malicious server can send can send a "literal" byte count, which is automatically read by the client's receiver thread. The response reader immediately allocates memory for the number of bytes indicated by the server response. This should not be an issue when securely connecting to trusted IMAP servers that are well-behaved. It can affect insecure connections and buggy, untrusted, or compromised servers (for example, connecting to a user supplied hostname). This issue has been patched in versions 0.5.7, 0.4.20, 0.3.9, and 0.2.5.

Publish Date: 2025-04-28

URL: CVE-2025-43857

CVSS 3 Score Details (7.5)

Base Score Metrics:

• Exploitability Metrics:
  • Attack Vector: Network
  • Attack Complexity: Low
  • Privileges Required: None
  • User Interaction: None
  • Scope: Unchanged
• Impact Metrics:
  • Confidentiality Impact: None
  • Integrity Impact: None
  • Availability Impact: High

For more information on CVSS3 Scores, click here.

Suggested Fix

Type: Upgrade version

Release Date: 2025-04-28

Fix Resolution: https://github.com/ruby/net-imap.git - v0.5.7

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