CVE-2025-4877

Publication date 25 June 2025

Last updated 29 August 2025

Ubuntu priority

Cvss 3 Severity Score

Description

There's a vulnerability in the libssh package where when a libssh consumer passes in an unexpectedly large input buffer to ssh_get_fingerprint_hash() function. In such cases the bin_to_base64() function can experience an integer overflow leading to a memory under allocation, when that happens it's possible that the program perform out of bounds write leading to a heap corruption. This issue affects only 32-bits builds of libssh.

Status

Show unmaintained releases

Package	Ubuntu Release	Status
libssh	25.04 plucky	Fixed 0.11.1-1ubuntu0.1
	24.10 oracular	Fixed 0.10.6-3ubuntu1.1
	24.04 LTS noble	Fixed 0.10.6-2ubuntu0.1
	22.04 LTS jammy	Fixed 0.9.6-2ubuntu0.22.04.4
	20.04 LTS focal	Fixed 0.9.3-2ubuntu2.5+esm1
	18.04 LTS bionic	Fixed 0.8.0~20170825.94fa1e38-1ubuntu0.7+esm4
	16.04 LTS xenial	Fixed 0.6.3-4.3ubuntu0.6+esm2

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Patch details

For informational purposes only. We recommend not to cherry-pick updates. How can I get the fixes?

Package	Patch details
libssh	Upstream: ?h=stab

Severity score breakdown

Parameter	Value
Base score	4.5 · Medium
Attack vector	Local
Attack complexity	High
Privileges required	Low
User interaction	None
Scope	Unchanged
Confidentiality	Low
Integrity impact	Low
Availability impact	Low
Vector	CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:L