CVE-2020-7211: tftp.c in libslirp 4.1.0, as used in QEMU 4.2.0, does not prevent ..\ directory traversal on Windows.

This month

HIGH 7.5REMOTEDOWNGRADEDOWNGRADE

CVE-2020-7211 is a high-severity flaw (CVSS 7.5) affecting libslirp, qemu. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

tftp.c in libslirp 4.1.0, as used in QEMU 4.2.0, does not prevent ..\ directory traversal on Windows.

Why this priority

High severity
EPSS top 9%: very likely to be exploited
Remotely exploitable, no login, no user action

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

Risk facts

CVSS score	7.5 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	4.2% (top 9%)
CISA exploited list	No
Weakness	CWE-22
Published	2020-01-21
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: libslirp project · qemu

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

Am I affected?

Timeline

2020-01-21 17:15 UTCPublished CVE record published
2026-06-17 03:24 UTCUpdated Record last modified

libslirp project libslirp DOWNGRADE

Affected: 4.1.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 4.1.0

1. Check installed version

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

2. No fixed release: DOWNGRADE to a release before 4.1.0 (Debian / Ubuntu)

apt-cache madison libslirp sudo apt install libslirp=<VERSION_BEFORE_4.1.0> sudo apt-mark hold libslirp

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

dnf --showduplicates list libslirp sudo dnf downgrade libslirp-<VERSION_BEFORE_4.1.0> sudo dnf versionlock add libslirp

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.

qemu qemu DOWNGRADE

Affected: 4.2.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 4.2.0

1. Check installed version

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

2. No fixed release: DOWNGRADE to a release before 4.2.0 (Debian / Ubuntu)

apt-cache madison qemu sudo apt install qemu=<VERSION_BEFORE_4.2.0> sudo apt-mark hold qemu

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

dnf --showduplicates list qemu sudo dnf downgrade qemu-<VERSION_BEFORE_4.2.0> sudo dnf versionlock add qemu

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.

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-2020-7211?

libslirp: downgrade or apply the listed mitigation; qemu: downgrade or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2020-7211 being exploited?

CVE-2020-7211 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-2020-7211 affect?

CVE-2020-7211 affects libslirp, qemu. Severity is high (CVSS 7.5). tftp.c in libslirp 4.1.0, as used in QEMU 4.2.0, does not prevent ..\ directory traversal on Windows.

How urgent is CVE-2020-7211?

Priority 54/100. High severity; EPSS top 9%: very likely to be exploited; Remotely exploitable, no login, no user action

Software pages

Windows vulnerabilities · QEMU vulnerabilities

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References

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