Skip to content

Add CVE-2025-43857: DoS vulnerability in net-imap #3560

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
wants to merge 1 commit into
base: master
Choose a base branch
from
+35 −0
Open

Add CVE-2025-43857: DoS vulnerability in net-imap #3560

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
35 changes: 35 additions & 0 deletions en/news/_posts/2025-04-28-dos-net-imap-cve-2025-43857.md
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1,35 @@
---
layout: news_post
title: "CVE-2025-43857: DoS vulnerability in net-imap"
author: "nevans"
translator:
date: 2025-04-28 03:00:00 +0000
tags: security
lang: en
---

There is a possibility for DoS by in the net-imap gem. This vulnerability has been assigned the CVE identifier [CVE-2025-43857]. We recommend upgrading the net-imap gem.

## Details

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 affects insecure connections and buggy, untrusted, or compromised servers (for example, connecting to a user supplied hostname).

Please update net-imap gem to version 0.2.5, 0.3.9, 0.4.20, 0.5.7, or later.

When connecting to untrusted servers or using an insecure connection, `max_response_size` and response handlers must be configured appropriately to limit memory consumption. See [GHSA-j3g3-5qv5-52mj] for more details.

## Affected versions

net-imap gem versions <= 0.2.4, 0.3.0 to 0.3.8, 0.4.0 to 0.4.19, and 0.5.0 to 0.5.6.

## Credits

Thanks to [Masamune] for discovering this issue.

## History

* Originally published at 2025-04-28 03:00:00 (UTC)

[CVE-2025-43857]: https://www.cve.org/CVERecord?id=CVE-2025-43857
[GHSA-j3g3-5qv5-52mj]: https://github.com/ruby/net-imap/security/advisories/GHSA-j3g3-5qv5-52mj
[Masamune]: https://hackerone.com/masamune_
Loading