CVE-2017-15906

Publication date 25 October 2017

Last updated 25 August 2025

Ubuntu priority

Cvss 3 Severity Score

Description

The process_open function in sftp-server.c in OpenSSH before 7.6 does not properly prevent write operations in readonly mode, which allows attackers to create zero-length files.

Read the notes from the security team

Status

Show unmaintained releases

Package	Ubuntu Release	Status
openssh	21.04 hirsute	Fixed 1:7.6p1-4
	20.10 groovy	Fixed 1:7.6p1-4
	20.04 LTS focal	Fixed 1:7.6p1-4
	19.10 eoan	Fixed 1:7.6p1-4
	19.04 disco	Fixed 1:7.6p1-4
	18.10 cosmic	Fixed 1:7.6p1-4
	18.04 LTS bionic	Fixed 1:7.6p1-4
	17.10 artful	Fixed 1:7.5p1-10ubuntu0.1
	17.04 zesty	Ignored end of life
	16.04 LTS xenial	Fixed 1:7.2p2-4ubuntu2.4
	14.04 LTS trusty	Fixed 1:6.6p1-2ubuntu2.10

Notes

leosilva

file structure and patch mismatch, some ajustments required

Patch details

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

Package	Patch details
openssh	Upstream: a698156

Severity score breakdown

Parameter	Value
Base score	5.3 · Medium
Attack vector	Network
Attack complexity	Low
Privileges required	None
User interaction	None
Scope	Unchanged
Confidentiality	None
Integrity impact	Low
Availability impact	None
Vector	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

References

Related Ubuntu Security Notices (USN)

USN-3538-1
OpenSSH vulnerabilities
22 January 2018