Description
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.
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | sudo | 1.8.31-1 | — |
| Debian 13 | sudo | 1.8.31-1 | — |
| Debian 12 | sudo | 1.8.31-1 | — |
| Debian 9 | sudo | 1.8.19p1-2.1+deb9u2 | DSA-4614-1 |
| Debian 8 | sudo | 1.8.10p3-1+deb8u7 | DLA-2094-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 18.04 LTS | sudo | 1.8.21p2-3ubuntu1.2 | USN-4263-1 |
| Ubuntu 16.04 LTS | sudo | 1.8.16-0ubuntu1.9 | USN-4263-1 |
Show 1 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro 14.04 LTS | sudo | 1.8.9p5-1ubuntu1.5+esm3 | USN-4263-2 |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 8 | sudo | 1.8.25p1-8.el8_1.1 | RHSA-2020:0487 |
| RHEL 7 | sudo +1 | 1.8.23-4.el7_7.2 | RHSA-2020:0540 |
| RHEL 6 | sudo +1 | 1.8.6p3-29.el6_10.3 | RHSA-2020:0726 |
Show 1 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 8.0 E4S | sudo | 1.8.25p1-4.el8_0.3 | RHSA-2020:0509 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP1 | sudo | 1.8.22-4.9.1 | SUSE-SU-2020:0408-1 |
| SLES 15 | sudo | 1.8.22-4.9.1 | SUSE-SU-2020:0408-1 |
| SLES 12 SP5 | sudo | 1.8.27-4.3.1 | SUSE-SU-2020:0409-1 |
| SLES 12 SP4 | sudo | 1.8.20p2-3.17.1 | SUSE-SU-2020:0406-1 |
| SLES 12 SP3 | sudo | 1.8.20p2-3.17.1 | SUSE-SU-2020:0406-1 |
Show 14 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 12 SP2 | sudo | 1.8.10p3-10.26.1 | SUSE-SU-2020:0407-1 |
| SLES 12 SP1 | sudo | 1.8.10p3-2.32.1 | SUSE-SU-2020:0390-1 |
| SLES for SAP 15 | sudo | 1.8.22-4.9.1 | SUSE-SU-2020:0408-1 |
| SLES for SAP 12 SP5 | sudo | 1.8.27-4.3.1 | SUSE-SU-2020:0409-1 |
| SLES for SAP 12 SP4 | sudo | 1.8.20p2-3.17.1 | SUSE-SU-2020:0406-1 |
| SLES for SAP 12 SP3 | sudo | 1.8.20p2-3.17.1 | SUSE-SU-2020:0406-1 |
| SLES for SAP 12 SP2 | sudo | 1.8.10p3-10.26.1 | SUSE-SU-2020:0407-1 |
| SLES for SAP 12 SP1 | sudo | 1.8.10p3-2.32.1 | SUSE-SU-2020:0390-1 |
| SLE HPC 15 | sudo | 1.8.22-4.9.1 | SUSE-SU-2020:0408-1 |
| SUSE OpenStack Cloud Crowbar 8 | sudo | 1.8.20p2-3.17.1 | SUSE-SU-2020:0406-1 |
| SUSE OpenStack Cloud 8 | sudo | 1.8.20p2-3.17.1 | SUSE-SU-2020:0406-1 |
| SUSE OpenStack Cloud 7 | sudo | 1.8.10p3-10.26.1 | SUSE-SU-2020:0407-1 |
| SUSE HPE Helion OpenStack 8 | sudo | 1.8.20p2-3.17.1 | SUSE-SU-2020:0406-1 |
| SUSE Enterprise Storage 5 | sudo | 1.8.20p2-3.17.1 | SUSE-SU-2020:0406-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | sudo | 1.9.7p2-1.4 | openSUSE-SU-2024:11413-1 |
| openSUSE Leap 15.1 | sudo | 1.8.22-lp151.5.6.1 | openSUSE-SU-2020:0244-1 |
Alpine
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.24 | sudo | 1.8.31-r0 | — |
| Alpine v3.23 | sudo | 1.8.31-r0 | — |
| Alpine v3.22 | sudo | 1.8.31-r0 | — |
| Alpine v3.21 | sudo | 1.8.31-r0 | — |
| Alpine v3.20 | sudo | 1.8.31-r0 | — |
Show 12 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.19 | sudo | 1.8.31-r0 | — |
| Alpine v3.18 | sudo | 1.8.31-r0 | — |
| Alpine v3.17 | sudo | 1.8.31-r0 | — |
| Alpine v3.16 | sudo | 1.8.31-r0 | — |
| Alpine v3.15 | sudo | 1.8.31-r0 | — |
| Alpine v3.14 | sudo | 1.8.31-r0 | — |
| Alpine v3.13 | sudo | 1.8.31-r0 | — |
| Alpine v3.12 | sudo | 1.8.31-r0 | — |
| Alpine v3.11 | sudo | 1.8.29-r2 | — |
| Alpine v3.10 | sudo | 1.8.27-r2 | — |
| Alpine v3.9 | sudo | 1.8.25_p1-r3 | — |
| Alpine v3.8 | sudo | 1.8.23-r4 | — |
Amazon Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Amazon Linux 2 | sudo +1 | 1.8.23-4.amzn2.2 | ALAS2-2020-1404 |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 8 | sudo | 1.8.25p1-8.el8_1.1 | ELSA-2020-0487 |
| Oracle Linux 7 | sudo +1 | 1.8.23-4.0.2.el7_7.2 | ELSA-2020-0540 |
Public exploits
Exploit or proof-of-concept code for this vulnerability is publicly available, which lowers the bar for attackers. Treat it as a reason to patch sooner.
Third-party code, not reviewed by us. Public PoCs are sometimes fake or contain malware. Read the code first and run it only in an isolated lab, against systems you are authorised to test.
Exploit-DB 2
- Sudo 1.8.25p - 'pwfeedback' Buffer Overflow EDB-48052 · local · Feb 6, 2020
- Sudo 1.8.25p - 'pwfeedback' Buffer Overflow (PoC) EDB-47995 · dos · Feb 4, 2020
GitHub 14 repositories · most starred shown
-
saleemrashid/sudo-cve-2019-18634 ★ 240 · Feb 7, 2020
Proof of Concept for CVE-2019-18634
-
Plazmaz/CVE-2019-18634 ★ 59 · Feb 7, 2020
A functional exploit for CVE-2019-18634, a BSS overflow in sudo's pwfeedback feature that allows for for privesc
-
aesophor/CVE-2019-18634 ★ 5 · Aug 1, 2021
My n-day exploit for CVE-2019-18634 (local privilege escalation)
-
chanbakjsd/CVE-2019-18634 ★ 3 · Apr 14, 2024
A reproduction of CVE-2019-18634, sudo privilege escalation with buffer overflow.
-
N1et/CVE-2019-18634 ★ 2 · Feb 13, 2020
An Python Exploit for Sudo vulnerability CVE-2019-18634
-
dukptkey/CVE-2019-18634 ★ 1 · Mar 9, 2020
exploit for sudo CVE-2019-18634
-
l0w3/CVE-2019-18634 ★ 0 · Dec 11, 2024
This repo contains both the exploit and the explaination of how this vulnerability is exploited
-
DDayLuong/CVE-2019-18634 ★ 0 · Dec 27, 2023
-
paras1te-x/CVE-2019-18634 ★ 0 · May 5, 2021
exploit
-
edsonjt81/sudo-cve-2019-18634 ★ 0 · Apr 25, 2021
Sources: PoC-in-GitHub, Metasploit Framework, Exploit-DB — updated daily. Only links are listed; no exploit code is hosted here.
Advisories 18
- RHSA-2020:0726 Red Hat Security Advisory: sudo security update Red Hat Security Advisories (RHSA) · Jun 26, 2026
- RHSA-2020:0540 Red Hat Security Advisory: sudo security update Red Hat Security Advisories (RHSA) · Jun 26, 2026
- DSA-4614-1 sudo - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DLA-2094-1 sudo - security update Debian Security (DSA / DLA) · Mar 9, 2026
- USN-4263-1 sudo vulnerability Ubuntu Security Notices (USN) · Feb 10, 2026
- USN-4263-2 sudo vulnerability Ubuntu Security Notices (USN) · Feb 10, 2026
- SUSE-SU-2020:0407-1 Security update for sudo SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2020:0390-1 Security update for sudo SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2020:0408-1 Security update for sudo SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2020:0244-1 Security update for sudo SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2020:0409-1 Security update for sudo SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2024:11413-1 sudo-1.9.7p2-1.4 on GA media SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2020:0406-1 Security update for sudo SUSE / openSUSE Security Updates · Feb 4, 2026
- RHSA-2020:0509 Red Hat Security Advisory: sudo security update Red Hat Security Advisories (RHSA) · Nov 22, 2025
- RHSA-2020:0487 Red Hat Security Advisory: sudo security update Red Hat Security Advisories (RHSA) · Nov 22, 2025
- ALAS2-2020-1404 Important: sudo security update (Amazon Linux 2) Amazon Linux Security Center (ALAS) · Mar 18, 2020
- ELSA-2020-0540 Important: sudo security update (Oracle Linux 7) Oracle Linux Security Advisories (ELSA) · Feb 19, 2020
- ELSA-2020-0487 Important: sudo security update (Oracle Linux 8) Oracle Linux Security Advisories (ELSA) · Feb 13, 2020
References
- https://support.apple.com/kb/HT210919
- 20200129 APPLE-SA-2020-1-28-2 macOS Catalina 10.15.3, Security Update 2020-001 Mojave, Security Update 2020-001 High Sierra mailing-list
- https://www.sudo.ws/security.html
- https://www.sudo.ws/alerts/pwfeedback.html
- [oss-security] 20200130 CVE-2019-18634: buffer overflow in sudo when pwfeedback is enabled mailing-list
- [oss-security] 20200131 Re: CVE-2019-18634: buffer overflow in sudo when pwfeedback is enabled mailing-list
- 20200131 APPLE-SA-2020-1-28-2 macOS Catalina 10.15.3, Security Update 2020-001 Mojave, Security Update 2020-001 High Sierra mailing-list
- DSA-4614 vendor-advisory
- [debian-lts-announce] 20200201 [SECURITY] [DLA 2094-1] sudo security update mailing-list
- 20200203 [slackware-security] sudo (SSA:2020-031-01) mailing-list
- 20200203 [SECURITY] [DSA 4614-1] sudo security update mailing-list
- http://packetstormsecurity.com/files/156174/Slackware-Security-Advisory-sudo-Updates.html
- http://packetstormsecurity.com/files/156189/Sudo-1.8.25p-Buffer-Overflow.html
- [oss-security] 20200205 Re: CVE-2019-18634: buffer overflow in sudo when pwfeedback is enabled mailing-list
- [oss-security] 20200205 Re: CVE-2019-18634: buffer overflow in sudo when pwfeedback is enabled mailing-list
- USN-4263-1 vendor-advisory
- https://security.netapp.com/advisory/ntap-20200210-0001/
- USN-4263-2 vendor-advisory
- RHSA-2020:0487 vendor-advisory
- RHSA-2020:0509 vendor-advisory
- RHSA-2020:0540 vendor-advisory
- openSUSE-SU-2020:0244 vendor-advisory
- FEDORA-2020-8b563bc5f4 vendor-advisory
- RHSA-2020:0726 vendor-advisory
- GLSA-202003-12 vendor-advisory
- FEDORA-2020-7c1b270959 vendor-advisory