CVE-2019-18634

Exp

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.

Published: 2020-01-29 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2019-18634 is rated High Exploit Risk (80.9/100): CVSS High severity, with high exploitation likelihood (EPSS 88.01%, 99th percentile). 4 public exploit reference(s) are indexed (Exploit-DB). Public exploits are available—assess exposure, apply mitigations, and prioritize patching.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Public exploit references (Exploit-DB) for CVE-2019-18634

EDB-ID Source Kind Published Link
48052 exploit_db edb 2020-02-06 Exploit-DB ↗
47995 exploit_db edb 2020-02-04 Exploit-DB ↗
— nvd_ref exploit_tag Exploit-DB ↗
— nvd_ref exploit_tag Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2019-18634

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-05-26 88.13% 88.01% -0.12%
2 2026-05-22 88.01% 88.13% +0.12%
3 2026-05-09 — 88.01% —

Full EPSS history (23 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2019-18634

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.8 3.1 HIGH
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 1.8 5.9 [email protected]
4.6 2.0 MEDIUM
AV:L/AC:L/Au:N/C:P/I:P/A:P Click to expand
Access vector (AV:L)
Requires local access to the target system.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:P)
Partial integrity impact.
Availability impact (A:P)
Partial availability impact.
 3.9 6.4 [email protected]

Weakness enumeration for CVE-2019-18634

OS Trackers for CVE-2019-18634

vendor priority summary link
alpine high CVE-2019-18634: 1 source package rows (sudo); 14 state rows across 11 repos (3.10-main, 3.11-main, 3.12-main, 3.17-community, 3.18-community, 3.19-community, 3.20-community, 3.21-community, 3.22-community, edge-community, edge-main); fixed 11, open 3. https://security.alpinelinux.org/vuln/CVE-2019-18634
debian not yet assigned CVE-2019-18634 not yet assigned priority: Debian including 1 source packages (sudo), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2019-18634
gentoo high CVE-2019-18634: 1 GLSA(s) (202003-12), 1 atom(s) (app-admin/sudo); latest impact high. https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2019-18634
redhat high — https://access.redhat.com/security/cve/CVE-2019-18634
suse high CVE-2019-18634 severity important: SUSE including 290 source package names (1.1.1.0.1.5.157:sudo-1.8.22-4.9.1, 1.2.0.0.1.5.158:sudo-1.8.22-4.9.1, …), 350 product×package rows across 84 product lines (Container ses/6/cephcsi/cephcsi, Container ses/6/rook/ceph, … (84 product lines)): Fixed 205, Known Affected 142, Known Not Affected 3. https://www.suse.com/security/cve/CVE-2019-18634/
ubuntu low CVE-2019-18634 low priority: Ubuntu including 1 source packages (sudo), 5 status rows across 5 suites (bionic, eoan, trusty, upstream, xenial): released 5. https://ubuntu.com/security/CVE-2019-18634

Affected software / configurations for CVE-2019-18634

Vendor Product Version Raw CPE
sudo_project sudo >= 1.7.1, < 1.8.26 cpe:2.3:a:sudo_project:sudo:*:*:*:*:*:*:*:*
debian debian_linux 8.0 cpe:2.3:o:debian:debian_linux:8.0:*:*:*:*:*:*:*
debian debian_linux 9.0 cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*
debian debian_linux 10.0 cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*

References for CVE-2019-18634

URL Tags
http://lists.opensuse.org/opensuse-security-announce/2020-02/msg00029.html
http://packetstormsecurity.com/files/156174/Slackware-Security-Advisory-sudo-Updates.html Third Party Advisory VDB Entry
http://packetstormsecurity.com/files/156189/Sudo-1.8.25p-Buffer-Overflow.html Third Party Advisory VDB Entry
http://seclists.org/fulldisclosure/2020/Jan/40 Mailing List Third Party Advisory
http://www.openwall.com/lists/oss-security/2020/01/30/6 Mailing List Third Party Advisory
http://www.openwall.com/lists/oss-security/2020/01/31/1 Mailing List Third Party Advisory
http://www.openwall.com/lists/oss-security/2020/02/05/2 Third Party Advisory
http://www.openwall.com/lists/oss-security/2020/02/05/5 Exploit Third Party Advisory
https://access.redhat.com/errata/RHSA-2020:0487
https://access.redhat.com/errata/RHSA-2020:0509
https://access.redhat.com/errata/RHSA-2020:0540
https://access.redhat.com/errata/RHSA-2020:0726
https://lists.debian.org/debian-lts-announce/2020/02/msg00002.html Mailing List Third Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/I6TKF36KOQUVJNBHSVJFA7BU3CCEYD2F/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/IY6DZ7WMDKU4ZDML6MJLDAPG42B5WVUC/
https://seclists.org/bugtraq/2020/Feb/2 Mailing List Third Party Advisory
https://seclists.org/bugtraq/2020/Feb/3 Mailing List Third Party Advisory
https://seclists.org/bugtraq/2020/Jan/44 Mailing List Third Party Advisory
https://security.gentoo.org/glsa/202003-12
https://security.netapp.com/advisory/ntap-20200210-0001/
https://support.apple.com/kb/HT210919 Third Party Advisory
https://usn.ubuntu.com/4263-1/
https://usn.ubuntu.com/4263-2/
https://www.debian.org/security/2020/dsa-4614 Third Party Advisory
https://www.sudo.ws/alerts/pwfeedback.html Exploit Vendor Advisory
https://www.sudo.ws/security.html Vendor Advisory
cvelogic Threat Intelligence