Bug 2362749 (CVE-2025-43857)

Summary: CVE-2025-43857 net-imap: net-imap rubygem vulnerable to possible DoS by memory exhaustion
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: akostadi, amasferr, cbartlet, dmayorov, jcantril, jlledo, jvasik, kaycoth, mmakovy, periklis, rblanco, rojacob, tjochec, vmugicag, vondruch
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
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A flaw was found in Net::IMAP, a Ruby library for IMAP client functionality. This vulnerability allows a malicious server to send a large "literal" byte count, causing the client to allocate excessive memory, potentially leading to denial of service (memory exhaustion). This vulnerability could allow an attacker to overload the system's memory, causing performance degradation or crashes when connecting to untrusted or compromised IMAP servers.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
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Bug Depends On: 2362833, 2362835, 2362836    
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Description OSIDB Bzimport 2025-04-28 17:01:16 UTC 
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.