CVE-2018-1000001

Publication date 11 January 2018

Last updated 25 August 2025

Ubuntu priority

High

Why this priority?

Cvss 3 Severity Score

7.8 · High

Score breakdown

Description

In glibc 2.26 and earlier there is confusion in the usage of getcwd() by realpath() which can be used to write before the destination buffer leading to a buffer underflow and potential code execution.

From the Ubuntu Security Team

libc does not account for all the possible return values from the kernel getcwd(2) syscall; arbitrary code execution may result from applications making further assumptions on the return value from the getcwd(3) libary function.

Read the notes from the security team

Status

Package Ubuntu Release Status
dietlibc 19.10 eoan
Not affected
19.04 disco
Not affected
18.10 cosmic Ignored end of life
18.04 LTS bionic
Not affected
17.10 artful Ignored end of life
17.04 zesty Ignored end of life
16.04 LTS xenial
Not affected
14.04 LTS trusty Not in release
eglibc 19.10 eoan Not in release
19.04 disco Not in release
18.10 cosmic Not in release
18.04 LTS bionic Not in release
17.10 artful Not in release
17.04 zesty Not in release
16.04 LTS xenial Not in release
14.04 LTS trusty
Fixed 2.19-0ubuntu6.14
glibc 19.10 eoan
Not affected
19.04 disco
Not affected
18.10 cosmic
Not affected
18.04 LTS bionic
Not affected
17.10 artful
Fixed 2.26-0ubuntu2.1
17.04 zesty Ignored end of life
16.04 LTS xenial
Fixed 2.23-0ubuntu10
14.04 LTS trusty Not in release
musl 19.10 eoan
Not affected
19.04 disco
Not affected
18.10 cosmic
Not affected
18.04 LTS bionic
Not affected
17.10 artful Ignored end of life
17.04 zesty Ignored end of life
16.04 LTS xenial
Fixed 1.1.9-1ubuntu0.1~esm2
14.04 LTS trusty
Fixed 0.9.15-1ubuntu0.1~esm1

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Notes

seth-arnold

I wonder where Go, busybox, and similar "do it ourselves" tools fit. I added dietlibc and musl to this page out of an abundance of caution. Someone should investigate.

sbeattie

introduced a regression in glusterfs geo-rep due to its usage of rsync. See redhat bug for compensating patch for rsync.

msalvatore

Unlike in glibc, this issue does not cause a buffer underflow in musl. Furthermore, realpath() does not call getcwd() in musl.

Patch details

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

Package Patch details
glibc
musl

Severity score breakdown

Parameter Value
Base score 7.8 · High
Attack vector Local
Attack complexity Low
Privileges required Low
User interaction None
Scope Unchanged
Confidentiality High
Integrity impact High
Availability impact High
Vector CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

References

Related Ubuntu Security Notices (USN)

    • USN-3534-1
    • GNU C Library vulnerabilities
    • 17 January 2018
    • USN-3536-1
    • GNU C Library vulnerability
    • 17 January 2018

Other references