Bug 2346900 (CVE-2025-26618)

Summary:	CVE-2025-26618 otp: erlang: SSH SFTP packet size not verified properly in Erlang OTP
Product:	[Other] Security Response	Reporter:	OSIDB Bzimport <bzimport>
Component:	vulnerability	Assignee:	Product Security DevOps Team <prodsec-dev>
Status:	NEW ---	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	CC:	bihu, eglynn, jjoyce, jschluet, lhh, lsvaty, mburns, mgarciac, pgrist
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
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Doc Text:	A flaw was found in the Erlang OTP library. When multiple SSH packets are received, they may be combined into a single SFTP packet that exceeds the maximum allowed size. This flaw allows an authenticated remote attacker to trigger excessive memory allocation and cause a denial of service.	Story Points:	---
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oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
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Description OSIDB Bzimport 2025-02-20 20:01:14 UTC

Erlang is a programming language and runtime system for building massively scalable soft real-time systems with requirements on high availability. OTP is a set of Erlang libraries, which consists of the Erlang runtime system, a number of ready-to-use components mainly written in Erlang. Packet size is not verified properly for SFTP packets. As a result when multiple SSH packets (conforming to max SSH packet size) are received by ssh, they might be combined into an SFTP packet which will exceed the max allowed packet size and potentially cause large amount of memory to be allocated. Note that situation described above can only happen for successfully authenticated users after completing the SSH handshake. This issue has been patched in OTP versions 27.2.4, 26.2.5.9, and 25.3.2.18. There are no known workarounds for this vulnerability.