CVE-2025-43857
Description
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.
How to fix
- ruby-lang net\0.2.5, 0.3.9, 0.4.20, 0.5.7 or later
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| ruby-lang net\ | \ ≤ v < 0.2.5, 0.3.0 ≤ v < 0.3.9, 0.4.0 ≤ v < 0.4.20, 0.5.0 ≤ v < 0.5.7 | 0.2.5, 0.3.9, 0.4.20, 0.5.7 |
Check your version
Choose the product and enter the version you run to see whether it falls in the affected range.
Attack Surface Management
See the assets tied to your domains, the technologies they run and known vulnerabilities in one list.