CVE-2020-17368: Firejail through 0.9.62 mishandles shell metacharacters during use of the --output or --output-stderr option,

Q: How do I fix CVE-2020-17368?

firejail: upgrade to newer than 0.9.62; debian linux: mitigate or apply the listed mitigation; fedora: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Q: Is CVE-2020-17368 being exploited?

CVE-2020-17368 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2020-17368 affect?

CVE-2020-17368 affects firejail, debian linux, fedora. Severity is critical (CVSS 9.8). Firejail through 0.9.62 mishandles shell metacharacters during use of the --output or --output-stderr option, which may lead to command injection.

Q: How urgent is CVE-2020-17368?

Priority 67/100. Critical severity; EPSS top 9%: very likely to be exploited; Remotely exploitable, no login, no user action; On your watchlist

This week

CRITICAL 9.8REMOTEWATCHLISTUPGRADEMITIGATEMITIGATE

CVE-2020-17368 is a critical-severity flaw (CVSS 9.8) affecting firejail, debian linux, fedora. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Firejail through 0.9.62 mishandles shell metacharacters during use of the --output or --output-stderr option, which may lead to command injection.

Why this priority

Critical severity
EPSS top 9%: very likely to be exploited
Remotely exploitable, no login, no user action
On your watchlist

A fixed release or distro patch exists.

Risk facts

CVSS score	9.8 (Critical)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	4.1% (top 9%)
CISA exploited list	No
Weakness	CWE-78
Published	2020-08-11
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: debian · fedoraproject · firejail project · opensuse

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

Am I affected?

Timeline

2020-08-11 16:15 UTCPublished CVE record published
2026-06-17 02:58 UTCUpdated Record last modified

firejail project firejail UPGRADE

Affected: <= 0.9.62

Fixed in: newer than 0.9.62

Safe to downgrade to: no unaffected older release

1. Check installed version

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

2. UPGRADE to newer than 0.9.62 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade firejail

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade firejail

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

debian debian linux MITIGATE

Affected: 9.0 · 10.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 9.0

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

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.

opensuse leap MITIGATE

Affected: 15.2

Fixed in: no fixed release known

Safe to downgrade to: a release before 15.2

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-2020-17368?

firejail: upgrade to newer than 0.9.62; debian linux: mitigate or apply the listed mitigation; fedora: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2020-17368 being exploited?

CVE-2020-17368 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-2020-17368 affect?

CVE-2020-17368 affects firejail, debian linux, fedora. Severity is critical (CVSS 9.8). Firejail through 0.9.62 mishandles shell metacharacters during use of the --output or --output-stderr option, which may lead to command injection.

How urgent is CVE-2020-17368?

Priority 67/100. Critical severity; EPSS top 9%: very likely to be exploited; Remotely exploitable, no login, no user action; On your watchlist

Software pages

Debian vulnerabilities

Related CVEs

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CVE-2020-17367 HIGH 7.8 UPGRADE MITIGATE Firejail through 0.9.62 does not honor the -- end-of-options indicator after the --output option, which may le

References

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