CVE-2019-18634Public exploit

Local root escalation via password-feedback buffer overflow

Published Jan 29, 2020 · Updated Aug 5, 2024

Stack-based buffer overflow in Sudo 1.7.1 through 1.8.30 allows local users to execute code as root via crafted password input. The getln() routine in src/tgetpass.c resets the remaining length after a line-erase write error but leaves the buffer pointer advanced, so subsequent input writes beyond the stack buffer. Exploitation requires pwfeedback in sudoers and local access to a password prompt; upstream does not enable that option by default.

CVSS severity7.8
High
EPSS probability19.43%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Stack-based buffer overflow in Sudo 1.7.1 through 1.8.30 allows local users to execute code as root via crafted password input. The getln() routine in src/tgetpass.c resets the remaining length after a line-erase write error but leaves the buffer pointer advanced, so subsequent input writes beyond the stack buffer. Exploitation requires pwfeedback in sudoers and local access to a password prompt; upstream does not enable that option by default.

The record

CVE
CVE-2019-18634
Published
Jan 29, 2020
Updated
Aug 5, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-121, T1068
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Jan 29, 2020CVE publishedPublication date reported by the CVE source.
  2. Aug 5, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

7.8NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
8.8SUSECVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
7.8Amazon LinuxCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
7.8Red HatCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-121Stack-based Buffer Overflow
T1068Exploitation for Privilege Escalation

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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