CVE-2019-18634: Buffer Overflow

Published Jan 28, 2020
·
Updated

Apple macOS Catalina is vulnerable to a stack-based buffer overflow, caused by improper bounds checking by the privileged sudo process. By sending an overly long string to the stdin of getln() in tgetpass.c., a local attacker could overflow a buffer and execute arbitrary code on the system.

Other sources

In Sudo before 1.8.26, if pwfeedback is enabled in /etc/sudoers, users can trigger a stack-based buffer overflow in the privileged sudo process. (pwfeedback is a default setting in Linux Mint and elementary OS; however, it is NOT the default for upstream and many other packages, and would exist only if enabled by an administrator.) The attacker needs to deliver a long string to the stdin of getln() in tgetpass.c.

MITRE

In Sudo before 1.8.31, if pwfeedback is enabled in /etc/sudoers, users can trigger a stack-based buffer overflow in the privileged sudo process. (pwfeedback is a default setting in Linux Mint and elementary OS; however, it is NOT the default for upstream and many other packages, and would exist only if enabled by an administrator.) The attacker needs to deliver a long string to the stdin of getln() in tgetpass.c.

Upstream patch:

https://github.com/sudo-project/sudo/commit/fa8ffeb17523494f0e8bb49a25e53635f4509078

References:

https://www.sudo.ws/alerts/pwfeedback.html https://www.openwall.com/lists/oss-security/2020/01/30/6

Red Hat

sudo. A buffer overflow issue was addressed with improved memory handling.

Credit

Apple

Affected Software

11 affected componentsFixes available
debian/sudo<=1.8.19p1-2.1, <=1.8.29-1, <=1.8.27-1, <=1.8.27-1+deb10u1, <=1.8.19p1-2.1+deb9u1
1.8.31-11.8.27-1+deb10u21.8.19p1-2.1+deb9u2
redhat/sudo<1.8.31
1.8.31
IBM Data Risk Manager<=2.0.6
Apple macOS Catalina<10.15.3
10.15.3
Apple Mojave
Apple High Sierra
Sudo Project Sudo>=1.7.1<1.8.26
Debian Debian Linux=8.0
Debian Debian Linux=9.0
Debian Debian Linux=10.0
debian/sudo
1.9.5p2-3+deb11u11.9.5p2-3+deb11u31.9.13p3-1+deb12u31.9.13p3-1+deb12u21.9.16p2-31.9.17p2-4

Event History

Jan 29, 2020
CVE Published
via MITRE·05:23 PM
Data Sourced
via MITRE·05:23 PM
Description
Data Sourced
via NVD·06:15 PM
DescriptionSeverityWeaknessAffected Software
Feb 21, 2026
Data Sourced
via Ubuntu·12:24 AM
RemedyDescriptionSeverityAffected Software
Data Sourced
via Debian·12:24 AM
DescriptionAffected Software
Data Sourced
via Launchpad·12:24 AM
Description

Parent advisories

This vulnerability appears in the following advisories.

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Frequently Asked Questions

1

What is CVE-2019-18634?

CVE-2019-18634 is a vulnerability in sudo that allows for a buffer overflow attack due to memory handling issues.

2

What software is affected by CVE-2019-18634?

CVE-2019-18634 affects macOS Catalina (up to version 10.15.3), Mojave, and High Sierra.

3

How can I fix CVE-2019-18634?

To fix CVE-2019-18634, update your Apple macOS to version 10.15.3 or install the latest security updates for Mojave or High Sierra.

4

What is the severity of CVE-2019-18634?

The severity of CVE-2019-18634 is not specified in the description.

5

Where can I find more information about CVE-2019-18634?

More information about CVE-2019-18634 can be found at the following reference: [https://support.apple.com/en-us/HT210919](https://support.apple.com/en-us/HT210919)

Contact

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