CVE-2019-18634

HIGH

sudo 1.7.1-1.8.25 - Stack-based Buffer Overflow via pwfeedback

Title source: llm
STIX 2.1

Exploitation Summary

EIP tracks 19 public exploits for CVE-2019-18634. PoCs published by Dylan Katz, Joe Vennix, lockedbyte.

AI-analyzed exploit summary This exploit leverages a buffer overflow in sudo's askpass feature (CVE-2019-18634) to achieve local privilege escalation. It uses a crafted payload to manipulate memory and execute arbitrary code as root via a SUID binary.

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.

Exploits (19)

exploitdb WORKING POC
by Dylan Katz · bashlocallinux
https://www.exploit-db.com/exploits/48052

This exploit leverages a buffer overflow in sudo's askpass feature (CVE-2019-18634) to achieve local privilege escalation. It uses a crafted payload to manipulate memory and execute arbitrary code as root via a SUID binary.

Classification
Working Poc 95%
Attack Type
Lpe
Complexity
Moderate
Reliability
Reliable
Target: sudo versions 1.8.25p to 1.8.31p2
Auth required
Prerequisites: local access · socat installed or downloadable · gcc for compiling the helper binary
mistral-large-3 · analyzed Feb 16, 2026 Full analysis →
exploitdb WORKING POC
by Joe Vennix · textdoslinux
https://www.exploit-db.com/exploits/47995

This exploit demonstrates a stack-based buffer overflow in Sudo versions prior to 1.8.26 when the pwfeedback option is enabled. The PoC triggers a segmentation fault by piping a large input to sudo, potentially allowing privilege escalation to root.

Classification
Working Poc 90%
Attack Type
Lpe
Complexity
Trivial
Reliability
Reliable
Target: Sudo prior to 1.8.26
No auth needed
Prerequisites: pwfeedback enabled in sudoers file
mistral-large-3 · analyzed Feb 16, 2026 Full analysis →
github WORKING POC 690 stars
by lockedbyte · cpoc
https://github.com/lockedbyte/CVE-Exploits/tree/master/CVE-2019-18634

This repository contains a functional exploit for CVE-2019-18634, a buffer overflow in sudo's tgetpass.c when pwfeedback is enabled. The exploit leverages a pseudo-terminal to trigger the overflow, manipulate internal structures, and escalate privileges to root.

Classification
Working Poc 100%
Attack Type
Lpe
Complexity
Moderate
Reliability
Reliable
Target: sudo < 1.8.30
No auth needed
Prerequisites: sudo with pwfeedback enabled · access to a vulnerable system
mistral-large-3 · analyzed Feb 27, 2026 Full analysis →
nomisec WORKING POC 234 stars
by saleemrashid · poc
https://github.com/saleemrashid/sudo-cve-2019-18634

This repository contains a functional exploit for CVE-2019-18634, a buffer overflow vulnerability in sudo's pwfeedback feature. The exploit leverages a pseudo-terminal to trigger the overflow, overwrite critical structures, and escalate privileges to root by re-executing the exploit as the askpass program.

Classification
Working Poc 100%
Attack Type
Lpe
Complexity
Complex
Reliability
Reliable
Target: sudo versions 1.8.25p1 to 1.8.30
No auth needed
Prerequisites: Access to a vulnerable sudo binary · Ability to execute the exploit on the target system
mistral-large-3 · analyzed Feb 19, 2026 Full analysis →
nomisec WORKING POC 58 stars
by Plazmaz · poc
https://github.com/Plazmaz/CVE-2019-18634

This repository contains a functional exploit for CVE-2019-18634, a heap buffer overflow in sudo <=1.8.30 when pwfeedback is enabled. The exploit leverages a crafted input to achieve local privilege escalation by manipulating memory structures and executing arbitrary code.

Classification
Working Poc 95%
Attack Type
Lpe
Complexity
Complex
Reliability
Reliable
Target: sudo <=1.8.30
No auth needed
Prerequisites: sudo with pwfeedback enabled · socat installed
mistral-large-3 · analyzed Feb 19, 2026 Full analysis →
nomisec WORKING POC 5 stars
by aesophor · poc
https://github.com/aesophor/CVE-2019-18634

This repository contains a functional exploit for CVE-2019-18634, a buffer overflow vulnerability in sudo's pwfeedback feature. The exploit leverages a heap-based overflow to achieve local privilege escalation by manipulating memory structures and executing a reverse shell.

Classification
Working Poc 95%
Attack Type
Lpe
Complexity
Moderate
Reliability
Reliable
Target: sudo 1.8.25
Auth required
Prerequisites: sudo 1.8.25 with pwfeedback enabled · local access to the target system · Python3 and pwntools installed
mistral-large-3 · analyzed Feb 19, 2026 Full analysis →
nomisec WORKING POC 2 stars
by chanbakjsd · poc
https://github.com/chanbakjsd/CVE-2019-18634

This repository contains a functional exploit for CVE-2019-18634, a privilege escalation vulnerability in sudo when pwfeedback is enabled. The exploit leverages a buffer overflow to manipulate user details and escalate privileges to root.

Classification
Working Poc 95%
Attack Type
Lpe
Complexity
Moderate
Reliability
Reliable
Target: sudo version 1.8.25
Auth required
Prerequisites: sudo with pwfeedback enabled · access to a vulnerable system
mistral-large-3 · analyzed Feb 19, 2026 Full analysis →
nomisec WORKING POC 2 stars
by N1et · poc
https://github.com/N1et/CVE-2019-18634

This repository contains a functional exploit for CVE-2019-18634, a buffer overflow vulnerability in Sudo. The exploit leverages a heap-based buffer overflow in the `sudo` command to achieve local privilege escalation by manipulating the `SUDO_ASKPASS` environment variable and executing a crafted payload.

Classification
Working Poc 95%
Attack Type
Lpe
Complexity
Moderate
Reliability
Reliable
Target: Sudo (versions 1.8.26 to 1.8.30)
No auth needed
Prerequisites: Local access to the target system · Sudo version vulnerable to CVE-2019-18634
mistral-large-3 · analyzed Feb 19, 2026 Full analysis →
nomisec WORKING POC 1 stars
by dukptkey · poc
https://github.com/dukptkey/CVE-2019-18634

This exploit leverages CVE-2019-18634, a sudo vulnerability where improper handling of pseudo-terminals and environment variables allows local privilege escalation. The PoC manipulates sudo's tgetpass function to execute a shell with root privileges by crafting a specific payload and environment setup.

Classification
Working Poc 95%
Attack Type
Lpe
Complexity
Moderate
Reliability
Reliable
Target: sudo (versions affected by CVE-2019-18634)
No auth needed
Prerequisites: Local access to the system · sudo installed and vulnerable to CVE-2019-18634
mistral-large-3 · analyzed May 30, 2026 Full analysis →
nomisec WORKING POC 1 stars
by ptef · poc
https://github.com/ptef/CVE-2019-18634

This repository contains a functional exploit for CVE-2019-18634, a sudo vulnerability that allows local privilege escalation by manipulating the SUDO_ASKPASS environment variable and exploiting a buffer overflow in the pwfeedback feature. The exploit is tailored for Linux Mint 19.1 but may work on other distributions with adjustments.

Classification
Working Poc 95%
Attack Type
Lpe
Complexity
Moderate
Reliability
Reliable
Target: sudo (versions with pwfeedback enabled)
No auth needed
Prerequisites: Local access to the target system · sudo with pwfeedback enabled
mistral-large-3 · analyzed Feb 19, 2026 Full analysis →
nomisec WRITEUP
by Moscvv · poc
https://github.com/Moscvv/thm-cybersec-portfolio

This repository contains detailed technical writeups for multiple vulnerabilities, including CVE-2019-18634 (sudo buffer overflow via pwfeedback). The analysis covers root cause, exploitation mechanics, and mitigation strategies, but does not include functional exploit code. The content is educational and demonstrates deep technical understanding of the vulnerabilities.

Classification
Writeup 98%
Attack Type
Lpe
Complexity
Moderate
Reliability
Reliable
Target: sudo < 1.8.26 with pwfeedback enabled
Auth required
Prerequisites: pwfeedback enabled in /etc/sudoers · sudo version < 1.8.26 · low-privilege shell access
mistral-large-3 · analyzed Jul 07, 2026 Full analysis →
nomisec WRITEUP
by CyrusRazavi · poc
https://github.com/CyrusRazavi/CVE-2019-18634-writeup

This repository provides a detailed technical analysis of CVE-2019-18634, a heap buffer overflow in Sudo's pwfeedback function. It includes steps to verify the vulnerability, exploit it using a known PoC, and explains the root cause involving static heap buffer overflow leading to segmentation faults.

Classification
Writeup 90%
Attack Type
Lpe
Complexity
Moderate
Reliability
Reliable
Target: Sudo < 1.8.26
Auth required
Prerequisites: Vulnerable version of Sudo (< 1.8.26) · pwfeedback enabled in sudoers file
mistral-large-3 · analyzed Feb 19, 2026 Full analysis →
nomisec STUB
by letsr00t · poc
https://github.com/letsr00t/-CVE-2019-18634-sudo-pwfeedback

The repository contains only a README.md file with minimal content, lacking any functional exploit code or technical details about CVE-2019-18634. It appears to be a placeholder without substantive information.

Classification
Stub 90%
Attack Type
Other
Complexity
Trivial
Reliability
Theoretical
Target: sudo (pwfeedback vulnerability)
No auth needed
mistral-large-3 · analyzed Feb 19, 2026 Full analysis →
nomisec WORKING POC
by ngyinkit · poc
https://github.com/ngyinkit/cve-2019-18634

This repository contains a functional exploit for CVE-2019-18634, a sudo vulnerability. The exploit leverages a buffer overflow in sudo's pwfeedback feature to achieve local privilege escalation by injecting a reverse shell payload.

Classification
Working Poc 90%
Attack Type
Lpe
Complexity
Moderate
Reliability
Reliable
Target: sudo (versions 1.8.2 to 1.8.30)
No auth needed
Prerequisites: Local access to the target system · sudo installed and vulnerable version in use
mistral-large-3 · analyzed Feb 19, 2026 Full analysis →
nomisec WORKING POC
by l0w3 · poc
https://github.com/l0w3/CVE-2019-18634

This repository contains a functional exploit for CVE-2019-18634, a BSS-based buffer overflow in Sudo versions < 1.8.25 when pwfeedback is enabled. The exploit leverages a pseudo-terminal to trigger the vulnerability and achieve privilege escalation to root via a reverse shell.

Classification
Working Poc 95%
Attack Type
Lpe
Complexity
Moderate
Reliability
Reliable
Target: Sudo < 1.8.25
No auth needed
Prerequisites: pwfeedback enabled in sudoers file · Sudo version < 1.8.25
mistral-large-3 · analyzed Feb 19, 2026 Full analysis →
nomisec WORKING POC
by DDayLuong · poc
https://github.com/DDayLuong/CVE-2019-18634

This repository contains a functional exploit for CVE-2019-18634, a local privilege escalation vulnerability in sudo. The exploit leverages a buffer overflow in the sudo command's handling of the SUDO_ASKPASS environment variable to achieve root privileges.

Classification
Working Poc 95%
Attack Type
Lpe
Complexity
Moderate
Reliability
Reliable
Target: sudo versions 1.8.25p through 1.8.31p2
No auth needed
Prerequisites: Local access to the target system · socat installed or available for download
mistral-large-3 · analyzed Feb 19, 2026 Full analysis →
nomisec WORKING POC
by TheJoyOfHacking · poc
https://github.com/TheJoyOfHacking/saleemrashid-sudo-cve-2019-18634

This repository contains a functional exploit for CVE-2019-18634, a buffer overflow vulnerability in sudo's pwfeedback feature. The exploit leverages a pseudo-terminal to trigger the overflow, overwrite critical structures, and escalate privileges to root.

Classification
Working Poc 100%
Attack Type
Lpe
Complexity
Complex
Reliability
Reliable
Target: sudo versions 1.8.25p1 to 1.8.30
No auth needed
Prerequisites: Access to a vulnerable sudo binary · Ability to execute the exploit on the target system
mistral-large-3 · analyzed Feb 19, 2026 Full analysis →
nomisec WORKING POC
by paras1te-x · poc
https://github.com/paras1te-x/CVE-2019-18634

This repository contains a functional Python exploit for CVE-2019-18634, a sudo vulnerability affecting versions 1.8.25 and earlier. The exploit leverages a heap-based buffer overflow to achieve local privilege escalation by injecting a crafted payload via the SUDO_ASKPASS environment variable.

Classification
Working Poc 95%
Attack Type
Lpe
Complexity
Moderate
Reliability
Reliable
Target: sudo version 1.8.25 and earlier
No auth needed
Prerequisites: Local access to the target system · sudo version 1.8.25 or earlier
mistral-large-3 · analyzed Feb 19, 2026 Full analysis →
nomisec WORKING POC
by edsonjt81 · poc
https://github.com/edsonjt81/sudo-cve-2019-18634

This repository contains a functional exploit for CVE-2019-18634, a buffer overflow vulnerability in sudo's pwfeedback feature. The exploit leverages a pseudo-terminal to trigger the overflow, overwrite critical structures, and escalate privileges to root by re-executing the exploit as the askpass program.

Classification
Working Poc 100%
Attack Type
Lpe
Complexity
Complex
Reliability
Reliable
Target: sudo versions 1.8.25p1 to 1.8.30
No auth needed
Prerequisites: Access to a vulnerable sudo binary · Ability to execute the exploit on the target system
mistral-large-3 · analyzed Feb 19, 2026 Full analysis →

References (26)

Core 26
Core References
Third Party Advisory x_refsource_confirm
https://support.apple.com/kb/HT210919
Mailing List, Third Party Advisory mailing-list x_refsource_bugtraq
https://seclists.org/bugtraq/2020/Jan/44
Vendor Advisory x_refsource_misc
https://www.sudo.ws/security.html
Exploit, Vendor Advisory x_refsource_confirm
https://www.sudo.ws/alerts/pwfeedback.html
Mailing List, Third Party Advisory mailing-list x_refsource_mlist
http://www.openwall.com/lists/oss-security/2020/01/30/6
Mailing List, Third Party Advisory mailing-list x_refsource_mlist
http://www.openwall.com/lists/oss-security/2020/01/31/1
Mailing List, Third Party Advisory mailing-list x_refsource_fulldisc
http://seclists.org/fulldisclosure/2020/Jan/40
Third Party Advisory vendor-advisory x_refsource_debian
https://www.debian.org/security/2020/dsa-4614
Mailing List, Third Party Advisory mailing-list x_refsource_mlist
https://lists.debian.org/debian-lts-announce/2020/02/msg00002.html
Mailing List, Third Party Advisory mailing-list x_refsource_bugtraq
https://seclists.org/bugtraq/2020/Feb/3
Mailing List, Third Party Advisory mailing-list x_refsource_bugtraq
https://seclists.org/bugtraq/2020/Feb/2
Third Party Advisory mailing-list x_refsource_mlist
http://www.openwall.com/lists/oss-security/2020/02/05/2
Exploit, Third Party Advisory mailing-list x_refsource_mlist
http://www.openwall.com/lists/oss-security/2020/02/05/5
Vendor Advisory vendor-advisory x_refsource_ubuntu
https://usn.ubuntu.com/4263-1/
Vendor Advisory x_refsource_confirm
https://security.netapp.com/advisory/ntap-20200210-0001/
Vendor Advisory vendor-advisory x_refsource_ubuntu
https://usn.ubuntu.com/4263-2/
Vendor Advisory vendor-advisory x_refsource_redhat
https://access.redhat.com/errata/RHSA-2020:0487
Vendor Advisory vendor-advisory x_refsource_redhat
https://access.redhat.com/errata/RHSA-2020:0509
Vendor Advisory vendor-advisory x_refsource_redhat
https://access.redhat.com/errata/RHSA-2020:0540
Vendor Advisory vendor-advisory x_refsource_redhat
https://access.redhat.com/errata/RHSA-2020:0726
Third Party Advisory vendor-advisory x_refsource_gentoo
https://security.gentoo.org/glsa/202003-12

Scores

CVSS v3 7.8
EPSS 0.1943
EPSS Percentile 97.1%
Attack Vector LOCAL
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Details

CWE
CWE-787
Status published
Products (4)
debian/debian_linux 8.0
debian/debian_linux 9.0
debian/debian_linux 10.0
sudo_project/sudo 1.7.1 - 1.8.26
Published Jan 29, 2020
Tracked Since Feb 18, 2026