#VU112026 Asymmetric Resource Consumption (Amplification) in net-imap - CVE-2025-25186
Published: June 27, 2025
Vulnerability identifier: #VU112026
Vulnerability risk: Medium
CVSSv4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: CVE-2025-25186
CWE-ID: CWE-405
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerable software:
net-imap
net-imap
Software vendor:
Ruby
Ruby
Description
The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.
The vulnerability exists due to application does not properly control consumption of internal resources in `net-imap`'s response parser. At any time while the client is connected, a malicious server can send can send highly compressed `uid-set` data which is automatically read by the client's receiver thread. The response parser uses `Range#to_a` to convert the `uid-set` data into arrays of integers, with no limitation on the expanded size of the ranges. A remote attacker can trigger resource exhaustion and perform a denial of service (DoS) attack.
Remediation
Install updates from vendor's website.
External links
- https://github.com/ruby/net-imap/commit/70e3ddd071a94e450b3238570af482c296380b35
- https://github.com/ruby/net-imap/commit/c8c5a643739d2669f0c9a6bb9770d0c045fd74a3
- https://github.com/ruby/net-imap/commit/cb92191b1ddce2d978d01b56a0883b6ecf0b1022
- https://github.com/ruby/net-imap/security/advisories/GHSA-7fc5-f82f-cx69