CVE-2020-24385: In MidnightBSD before 1.2.6 and 1.3 before August 2020, and FreeBSD before 7, a NULL pointer dereference was f

Q: How do I fix CVE-2020-24385?

midnightbsd: upgrade to 1.2.6; freebsd: upgrade to newer than 7.0. Exact commands for each OS are on this page.

Q: Is CVE-2020-24385 being exploited?

CVE-2020-24385 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-2020-24385 affect?

CVE-2020-24385 affects midnightbsd, freebsd. Severity is medium (CVSS 5.5). In MidnightBSD before 1.2.6 and 1.3 before August 2020, and FreeBSD before 7, a NULL pointer dereference was found in the Linux emulation layer that allows attackers to crash the running kernel. During binary interaction, td->td_emuldata in

Routine

MEDIUM 5.5UPGRADEUPGRADE

CVE-2020-24385 is a medium-severity flaw (CVSS 5.5) affecting midnightbsd, freebsd. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

In MidnightBSD before 1.2.6 and 1.3 before August 2020, and FreeBSD before 7, a NULL pointer dereference was found in the Linux emulation layer that allows attackers to crash the running kernel. During binary interaction, td->td_emuldata in sys/compat/linux/linux_emul.h is not getting initialized and returns NULL from em_find().

Why this priority

No elevated risk signals yet

A fixed release or distro patch exists.

Risk facts

CVSS score	5.5 (Medium)
Attack vector	Local
Attack complexity	Low
Privileges needed	Low
User interaction	None
EPSS exploit chance	0.4% (top 69%)
CISA exploited list	No
Weakness	CWE-476
Published	2020-09-03
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: freebsd · midnightbsd

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

Am I affected?

Timeline

2020-09-03 15:15 UTCPublished CVE record published
2026-06-17 03:05 UTCUpdated Record last modified

midnightbsd midnightbsd UPGRADE

Affected: < 1.2.6 · >= 1.3 and <= 2020-08-19

Fixed in: 1.2.6

Safe to downgrade to: a release before 1.3

1. Check installed version

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

2. UPGRADE to 1.2.6 (Debian / Ubuntu)

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

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade midnightbsd

Note

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

3. If no update is available yet, DOWNGRADE to a release before 1.3 (Debian / Ubuntu)

apt-cache madison midnightbsd sudo apt install midnightbsd=<VERSION_BEFORE_1.3> sudo apt-mark hold midnightbsd

3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list midnightbsd sudo dnf downgrade midnightbsd-<VERSION_BEFORE_1.3> sudo dnf versionlock add midnightbsd

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.

freebsd freebsd UPGRADE

Affected: <= 7.0

Fixed in: newer than 7.0

Safe to downgrade to: no unaffected older release

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-2020-24385?

midnightbsd: upgrade to 1.2.6; freebsd: upgrade to newer than 7.0. Exact commands for each OS are on this page.

Is CVE-2020-24385 being exploited?

CVE-2020-24385 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-2020-24385 affect?

CVE-2020-24385 affects midnightbsd, freebsd. Severity is medium (CVSS 5.5). In MidnightBSD before 1.2.6 and 1.3 before August 2020, and FreeBSD before 7, a NULL pointer dereference was found in the Linux emulation layer that allows attackers to crash the running kernel. During binary interaction, td->td_emuldata in

How urgent is CVE-2020-24385?

Priority 27/100. No elevated risk signals yet.

Related CVEs

CVE-2020-24863 MEDIUM 5.5 UPGRADE UPGRADE A memory corruption vulnerability was found in the kernel function kern_getfsstat in MidnightBSD before 1.2.7

References

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