CVE-2017-2635: A NULL pointer deference flaw was found in the way libvirt from 2.5.0 to 3.0.0 handled empty drives

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HIGH 7.7WATCHLISTUPGRADE

CVE-2017-2635 is a high-severity flaw (CVSS 7.7) affecting libvirt. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

A NULL pointer deference flaw was found in the way libvirt from 2.5.0 to 3.0.0 handled empty drives. A remote authenticated attacker could use this flaw to crash libvirtd daemon resulting in denial of service.

Why this priority

High severity
On your watchlist

A fixed release or distro patch exists.

Risk facts

CVSS score	7.7 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	Low
User interaction	None
EPSS exploit chance	1.5% (top 25%)
CISA exploited list	No
Weakness	CWE-476
Published	2018-08-22
Last modified	2026-06-17

Publisher (CNA): Red Hat, Inc. · Vendor: redhat

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

Am I affected?

Timeline

2018-08-22 21:29 UTCPublished CVE record published
2026-06-17 01:16 UTCUpdated Record last modified

redhat libvirt UPGRADE

Affected: >= 2.5.0 and <= 3.0.0

Fixed in: newer than 3.0.0

Safe to downgrade to: a release before 2.5.0

1. Check installed version

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

2. UPGRADE to newer than 3.0.0 (Debian / Ubuntu)

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

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade libvirt

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 2.5.0 (Debian / Ubuntu)

apt-cache madison libvirt sudo apt install libvirt=<VERSION_BEFORE_2.5.0> sudo apt-mark hold libvirt

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

dnf --showduplicates list libvirt sudo dnf downgrade libvirt-<VERSION_BEFORE_2.5.0> sudo dnf versionlock add libvirt

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-2017-2635?

libvirt: upgrade to newer than 3.0.0. Exact commands for each OS are on this page.

Is CVE-2017-2635 being exploited?

CVE-2017-2635 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-2017-2635 affect?

CVE-2017-2635 affects libvirt. Severity is high (CVSS 7.7). A NULL pointer deference flaw was found in the way libvirt from 2.5.0 to 3.0.0 handled empty drives. A remote authenticated attacker could use this flaw to crash libvirtd daemon resulting in denial of service.

How urgent is CVE-2017-2635?

Priority 51/100. High severity; On your watchlist

Related CVEs

CVE-2024-8235 MEDIUM 6.2 UPGRADE A flaw was found in libvirt
CVE-2024-2496 MEDIUM 5.0 UPGRADE MITIGATE A NULL pointer dereference flaw was found in the udevConnectListAllInterfaces() function in libvirt
CVE-2023-3750 MEDIUM 6.5 MITIGATE MITIGATE A flaw was found in libvirt
CVE-2023-2700 MEDIUM 5.5 DOWNGRADE MITIGATE A vulnerability was found in libvirt
CVE-2022-0897 MEDIUM 4.3 UPGRADE MITIGATE A flaw was found in the libvirt nwfilter driver

References

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