CVE-2017-12425: An issue was discovered in Varnish HTTP Cache 4.0.1 through 4.0.4, 4.1.0 through 4.1.7, 5.0.0, and 5.1.0 throu

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HIGH 7.5REMOTEDOWNGRADEDOWNGRADEDOWNGRADE

CVE-2017-12425 is a high-severity flaw (CVSS 7.5) affecting varnish, varnish cache, varnish cache. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

An issue was discovered in Varnish HTTP Cache 4.0.1 through 4.0.4, 4.1.0 through 4.1.7, 5.0.0, and 5.1.0 through 5.1.2. A wrong if statement in the varnishd source code means that particular invalid requests from the client can trigger an assert, related to an Integer Overflow. This causes the varnishd worker process to abort and restart, losing the cached contents in the process. An attacker can therefore crash the varnishd worker process on dem

Why this priority

High severity
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	2.4% (top 16%)
CISA exploited list	No
Weakness	CWE-190
Published	2017-08-04
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: varnish cache project · varnish-cache · varnish-software

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

Am I affected?

Timeline

2017-08-04 09:29 UTCPublished CVE record published
2026-06-17 01:03 UTCUpdated Record last modified

varnish-cache varnish DOWNGRADE

Affected: 4.0.2 rc-1 · 4.0.3 rc-1 · 4.0.3 rc-2 · 4.0.3 rc-2-proper · 4.0.3 rc-3 · 4.1.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 4.0.2

1. Check installed version

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

2. No fixed release: DOWNGRADE to a release before 4.0.2 (Debian / Ubuntu)

apt-cache madison varnish sudo apt install varnish=<VERSION_BEFORE_4.0.2> sudo apt-mark hold varnish

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

dnf --showduplicates list varnish sudo dnf downgrade varnish-<VERSION_BEFORE_4.0.2> sudo dnf versionlock add varnish

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.

varnish cache project varnish cache DOWNGRADE

Affected: 4.0.1 · 4.0.2 · 4.0.3 · 4.0.4 · 5.0.0 · 5.1.0 · 5.1.1 · 5.1.2

Fixed in: no fixed release known

Safe to downgrade to: a release before 4.0.1

1. Check installed version

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

2. No fixed release: DOWNGRADE to a release before 4.0.1 (Debian / Ubuntu)

apt-cache madison varnish-cache sudo apt install varnish-cache=<VERSION_BEFORE_4.0.1> sudo apt-mark hold varnish-cache

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

dnf --showduplicates list varnish-cache sudo dnf downgrade varnish-cache-<VERSION_BEFORE_4.0.1> sudo dnf versionlock add varnish-cache

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.

varnish-software varnish cache DOWNGRADE

Affected: 4.1.0 beta1 · 4.1.0 technology_preview1 · 4.1.1 · 4.1.1 beta1 · 4.1.1 beta2 · 4.1.2 · 4.1.2 beta1 · 4.1.2 beta2

Fixed in: no fixed release known

Safe to downgrade to: a release before 4.1.0

1. Check installed version

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

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

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

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

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

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-2017-12425?

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

Is CVE-2017-12425 being exploited?

CVE-2017-12425 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-2017-12425 affect?

CVE-2017-12425 affects varnish, varnish cache, varnish cache. Severity is high (CVSS 7.5). An issue was discovered in Varnish HTTP Cache 4.0.1 through 4.0.4, 4.1.0 through 4.1.7, 5.0.0, and 5.1.0 through 5.1.2. A wrong if statement in the varnishd source code means that particular invalid requests from the client can trigger an a

How urgent is CVE-2017-12425?

Priority 52/100. High severity; Remotely exploitable, no login, no user action

Software pages

Varnish vulnerabilities

Related CVEs

CVE-2017-8807 CRITICAL 9.1 UPGRADE UPGRADE vbf_stp_error in bin/varnishd/cache/cache_fetch.c in Varnish HTTP Cache 4.1.x before 4.1.9 and 5.x before 5.2.
CVE-2013-4484 MEDIUM 5.0 DOWNGRADE UPGRADE Varnish before 3.0.5 allows remote attackers to cause a denial of service (child-process crash and temporary c
CVE-2013-0325 MEDIUM 4.3 DOWNGRADE Multiple cross-site scripting (XSS) vulnerabilities in the Varnish module 6.x-1.x before 6.x-1.2 and 7.x-1.x b

References

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