CVE-2019-18634: 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 proc
Noroxi assessment
Priority: Monitor (action score 37/100)
- Public proof-of-concept code exists (Exploit-DB, GitHub); there is no record of exploitation in the wild.
- Probability of exploitation in the next 30 days: 19.2% (FIRST EPSS); higher than 97.3% of all records.
- Someone with local access to the system can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
- Fixed version: sudo (Alpine:v3.10) 1.8.27-r2; sudo (Alpine:v3.11) 1.8.29-r2; sudo (Alpine:v3.12) 1.8.31-r0.
Low priority for now. Upgrade to sudo (Alpine:v3.10) 1.8.27-r2; sudo (Alpine:v3.11) 1.8.29-r2; sudo (Alpine:v3.12) 1.8.31-r0 or later.
Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it
Primary sources: NVD · CVE.org · FIRST EPSS
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
- Jan 29, 2020
- Updated
- Jun 16, 2026
- EPSS
- 19.2% · 97th percentile
- CWE
- CWE-787
Report tools
Action score
37
Monitor
Low priority for now.
- CVSS
- 31 / 40 · 7.8 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 6 / 30 · 19.2%
Get told when this record changes
- Not in KEV: no record of exploitation in the wild
- Proof of concept exists, no weaponized module
- A fix has been released
If any of these changes, we'll tell you in the daily email digest.
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Noroxi analysis
What does it mean in your environment?
The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.
We use this product, ask for helpAffected systems
Is your version affected?
Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.
| Vendor | Product | CPE |
|---|---|---|
| sudo project | sudo | cpe:2.3:a:sudo_project:sudo |
| debian | debian linux | cpe:2.3:o:debian:debian_linux |
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- debian debian linux10.0
- debian debian linux8.0
- debian debian linux9.0
- sudo project sudo1.7.1 and later · before 1.8.26
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| Alpine:v3.10 | sudo | from 1.7.1 · before 1.8.27-r2 | 1.8.27-r2 |
| Alpine:v3.11 | sudo | from 1.7.1 · before 1.8.29-r2 | 1.8.29-r2 |
| Alpine:v3.12 | sudo | from 1.7.1 · before 1.8.31-r0 | 1.8.31-r0 |
| Alpine:v3.8 | sudo | from 1.7.1 · before 1.8.23-r4 | 1.8.23-r4 |
| Alpine:v3.9 | sudo | from 1.7.1 · before 1.8.25_p1-r3 | 1.8.25_p1-r3 |
| Debian:12 | sudo | before 1.8.31-1 | 1.8.31-1 |
| Debian:8 | sudo | before 1.8.10p3-1+deb8u7 | 1.8.10p3-1+deb8u7 |
| Debian:9 | sudo | before 1.8.19p1-2.1+deb9u2 | 1.8.19p1-2.1+deb9u2 |
| openSUSE:Leap 15.1 | sudo | before 1.8.22-lp151.5.6.1 | 1.8.22-lp151.5.6.1 |
| openSUSE:Tumbleweed | sudo | before 1.9.7p2-1.4 | 1.9.7p2-1.4 |
| Red Hat:enterprise_linux:6::client | sudo | before 0:1.8.6p3-29.el6_10.3 | 0:1.8.6p3-29.el6_10.3 |
| Red Hat:enterprise_linux:6::client | sudo-debuginfo | before 0:1.8.6p3-29.el6_10.3 | 0:1.8.6p3-29.el6_10.3 |
| Red Hat:enterprise_linux:6::client | sudo-devel | before 0:1.8.6p3-29.el6_10.3 | 0:1.8.6p3-29.el6_10.3 |
| Red Hat:enterprise_linux:7::client | sudo | before 0:1.8.23-4.el7_7.2 | 0:1.8.23-4.el7_7.2 |
| Red Hat:enterprise_linux:7::client | sudo-debuginfo | before 0:1.8.23-4.el7_7.2 | 0:1.8.23-4.el7_7.2 |
| Red Hat:enterprise_linux:7::client | sudo-devel | before 0:1.8.23-4.el7_7.2 | 0:1.8.23-4.el7_7.2 |
| Red Hat:enterprise_linux:8::baseos | sudo | before 0:1.8.25p1-8.el8_1.1 | 0:1.8.25p1-8.el8_1.1 |
| Red Hat:enterprise_linux:8::baseos | sudo-debuginfo | before 0:1.8.25p1-8.el8_1.1 | 0:1.8.25p1-8.el8_1.1 |
| Red Hat:enterprise_linux:8::baseos | sudo-debugsource | before 0:1.8.25p1-8.el8_1.1 | 0:1.8.25p1-8.el8_1.1 |
| Red Hat:rhel_e4s:8.0::baseos | sudo | before 0:1.8.25p1-4.el8_0.3 | 0:1.8.25p1-4.el8_0.3 |
| Red Hat:rhel_e4s:8.0::baseos | sudo-debuginfo | before 0:1.8.25p1-4.el8_0.3 | 0:1.8.25p1-4.el8_0.3 |
| Red Hat:rhel_e4s:8.0::baseos | sudo-debugsource | before 0:1.8.25p1-4.el8_0.3 | 0:1.8.25p1-4.el8_0.3 |
| SUSE:HPE Helion OpenStack 8 | sudo | before 1.8.20p2-3.17.1 | 1.8.20p2-3.17.1 |
| SUSE:Linux Enterprise Module for Basesystem 15 | sudo | before 1.8.22-4.9.1 | 1.8.22-4.9.1 |
+3
Same product
sudo project: all recordsOther highest-scoring records for the same primary product.
- CVE-2021-3156Sudo before 1.9.5p2 contains an off-by-one error that can result in a heap-based buffer overflow, which allows privilege escalation to root KEV91Now
- CVE-2025-32463Sudo before 1.9.17p1 allows local users to obtain root access because /etc/nsswitch.conf from a user-controlled directory is used with the -KEV78This week
- CVE-2019-14287In Sudo before 1.8.28, an attacker with access to a Runas ALL sudoer account can bypass certain policy blacklists and session PAM modules, a54Plan
Published before and after this one in the same product
- ← EarlierCVE-2016-7076May 29, 2018 · sudo before version 1.8.18p1 is vulnerable to a bypass in the sudo noexec restriction if application run via sudo executed wordexp() C libra31Monitor
- ← EarlierCVE-2019-18684Nov 4, 2019 · Sudo through 1.8.29 allows local users to escalate to root if they have write access to file descriptor 3 of the sudo process.28Monitor
- Later →CVE-2021-23239Jan 12, 2021 · The sudoedit personality of Sudo before 1.9.5 may allow a local unprivileged user to perform arbitrary directory-existence tests by winning 10Monitor
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| alpine:sudo | 1.8.27-r2 · Alpine:v3.10 | Package registry (OSV) |
| debian:sudo | 1.8.31-1 · Debian:12 | Package registry (OSV) |
| opensuse:sudo | 1.8.22-lp151.5.6.1 · openSUSE:Leap 15.1 | Package registry (OSV) |
| red hat:sudo | 0:1.8.25p1-8.el8_1.1 · Red Hat:enterprise_linux:8::baseos | Package registry (OSV) |
| red hat:sudo-debuginfo | 0:1.8.25p1-8.el8_1.1 · Red Hat:enterprise_linux:8::baseos | Package registry (OSV) |
| red hat:sudo-debugsource | 0:1.8.25p1-8.el8_1.1 · Red Hat:enterprise_linux:8::baseos | Package registry (OSV) |
| red hat:sudo-devel | 0:1.8.23-4.el7_7.2 · Red Hat:enterprise_linux:7::client | Package registry (OSV) |
| suse:sudo | 1.8.10p3-2.32.1 · SUSE:Linux Enterprise Server for SAP Applications 12 SP1 | Package registry (OSV) |
Exploit status
Proof of concept available
A public proof of concept or detection signature exists. Exploit knowledge is out there; don't delay patching.
Evidence
- Exploit-DB entry ×2
- Proof-of-concept repository on GitHub ×15
Noroxi does not host or link to exploit code. Metasploit module names and Nuclei template ids are shown (names, not code); Exploit-DB entries and PoC repositories are given as counts only.
| Source | Kind | Date |
|---|---|---|
| Exploit-DB entry | dos | 2020-02-04 |
| Exploit-DB entry | local | 2020-02-06 |
| Proof-of-concept repository on GitHub | stars:59 | 2020-02-07 |
| Proof-of-concept repository on GitHub | stars:239 | 2020-02-07 |
| Proof-of-concept repository on GitHub | stars:2 | 2020-02-13 |
| Proof-of-concept repository on GitHub | stars:1 | 2020-03-09 |
| Proof-of-concept repository on GitHub | stars:0 | 2021-04-25 |
| Proof-of-concept repository on GitHub | stars:0 | 2021-05-05 |
| Proof-of-concept repository on GitHub | stars:5 | 2021-08-01 |
| Proof-of-concept repository on GitHub | stars:0 | 2022-03-20 |
| Proof-of-concept repository on GitHub | stars:0 | 2023-12-27 |
| Proof-of-concept repository on GitHub | stars:3 | 2024-04-14 |
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
- Published
- First PoC+5 d
- TodayOct 26, 2026+2462 d
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
No commit or PR link among the references.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
No credits in the CNA record.
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
No nightly-computed relations.
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
—
Bug bounty scope
No known public program.
Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).
Technical details
Attack conditions
- Someone with local access to the system can trigger it.
- A low-privileged account is enough.
- No user action is required.
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- high · data can be read
- Integrity
- high · data or configuration can be modified
- Availability
- high · the service can be disrupted
- Attack vector
- Local
- Attack complexity
- Low
- Privileges required
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- High
- Integrity impact
- High
- Availability impact
- High
Weakness class (CWE)
CWE-787 · Out-of-bounds WriteCVSS vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
nvd-primary
Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
MITRE has no CAPEC/ATT&CK mapping for this CWE.
Change log
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
Show all references (19 more)Show less
- packetstormsecurity.com/files/156174/Slackware-Security-Advisory-sudo-Updates.html
- packetstormsecurity.com/files/156189/Sudo-1.8.25p-Buffer-Overflow.html
- seclists.org/fulldisclosure/2020/Jan/40
- www.openwall.com/lists/oss-security/2020/01/30/6
- www.openwall.com/lists/oss-security/2020/01/31/1
- www.openwall.com/lists/oss-security/2020/02/05/2
- access.redhat.com/errata/RHSA-2020:0487
- access.redhat.com/errata/RHSA-2020:0509
- access.redhat.com/errata/RHSA-2020:0540
- access.redhat.com/errata/RHSA-2020:0726
- lists.debian.org/debian-lts-announce/2020/02/msg00002.html
- lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/I6TKF36KOQUVJNBHSVJFA7BU3CCEYD2F/
- lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/IY6DZ7WMDKU4ZDML6MJLDAPG42B5WVUC/
- seclists.org/bugtraq/2020/Feb/2
- seclists.org/bugtraq/2020/Feb/3
- seclists.org/bugtraq/2020/Jan/44
- security.gentoo.org/glsa/202003-12
- security.netapp.com/advisory/ntap-20200210-0001/
- support.apple.com/kb/HT210919
Vendor advisories and official records. Exploit/PoC links are deliberately left out.