CVE-2019-19917: Lout 3.40 has a buffer overflow in the StringQuotedWord() function in z39.c.

This month

HIGH 7.8DOWNGRADEDOWNGRADEMITIGATE

CVE-2019-19917 is a high-severity flaw (CVSS 7.8) affecting lout, backports sle, leap. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Lout 3.40 has a buffer overflow in the StringQuotedWord() function in z39.c.

Why this priority

High severity
Public exploit reference

No fix is published yet: follow the downgrade or mitigation steps.

Risk facts

CVSS score	7.8 (High)
Attack vector	Local
Attack complexity	Low
Privileges needed	None
User interaction	Required
EPSS exploit chance	1.5% (top 25%)
CISA exploited list	No
Weakness	CWE-120
Published	2019-12-20
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: fedoraproject · lout project · opensuse

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2019-12-20 20:15 UTCPublished CVE record published
2026-06-17 02:27 UTCUpdated Record last modified

lout project lout DOWNGRADE

Affected: 3.40

Fixed in: no fixed release known

Safe to downgrade to: a release before 3.40

1. Check installed version

apt-cache policy lout || rpm -q lout || lout --version

2. No fixed release: DOWNGRADE to a release before 3.40 (Debian / Ubuntu)

apt-cache madison lout sudo apt install lout=<VERSION_BEFORE_3.40> sudo apt-mark hold lout

2. No fixed release: DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list lout sudo dnf downgrade lout-<VERSION_BEFORE_3.40> sudo dnf versionlock add lout

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

opensuse backports sle DOWNGRADE

Affected: 15.0 sp1 · 15.0 sp2

Fixed in: no fixed release known

Safe to downgrade to: a release before 15.0

1. Check installed version

apt-cache policy backports-sle || rpm -q backports-sle || backports-sle --version

2. No fixed release: DOWNGRADE to a release before 15.0 (Debian / Ubuntu)

apt-cache madison backports-sle sudo apt install backports-sle=<VERSION_BEFORE_15.0> sudo apt-mark hold backports-sle

2. No fixed release: DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list backports-sle sudo dnf downgrade backports-sle-<VERSION_BEFORE_15.0> sudo dnf versionlock add backports-sle

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

opensuse leap MITIGATE

Affected: 15.1 · 15.2

Fixed in: no fixed release known

Safe to downgrade to: a release before 15.1

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

fedoraproject fedora MITIGATE

Affected: 31 · 32 · 33

Fixed in: no fixed release known

Safe to downgrade to: a release before 31

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2019-19917?

lout: downgrade or apply the listed mitigation; backports sle: downgrade or apply the listed mitigation; leap: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2019-19917 being exploited?

CVE-2019-19917 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2019-19917 affect?

CVE-2019-19917 affects lout, backports sle, leap. Severity is high (CVSS 7.8). Lout 3.40 has a buffer overflow in the StringQuotedWord() function in z39.c.

How urgent is CVE-2019-19917?

Priority 51/100. High severity; Public exploit reference

Related CVEs

CVE-2019-19918 HIGH 7.8 DOWNGRADE DOWNGRADE Lout 3.40 has a heap-based buffer overflow in the srcnext() function in z02.c.

References

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