CVE-2020-25704: A flaw memory leak in the Linux kernel performance monitoring subsystem was found in the way if using PERF_EVE

Routine

MEDIUM 5.5WATCHLISTUPGRADEMITIGATEMITIGATE

CVE-2020-25704 is a medium-severity flaw (CVSS 5.5) affecting linux kernel, debian linux, command center. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

A flaw memory leak in the Linux kernel performance monitoring subsystem was found in the way if using PERF_EVENT_IOC_SET_FILTER. A local user could use this flaw to starve the resources causing denial of service.

Why this priority

On your watchlist

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 71%)
CISA exploited list	No
Weakness	CWE-401
Published	2020-12-02
Last modified	2026-06-17

Publisher (CNA): Red Hat, Inc. · Vendor: debian · linux · starwindsoftware

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

Am I affected?

Timeline

2020-12-02 01:15 UTCPublished CVE record published
2026-06-17 03:07 UTCUpdated Record last modified

linux linux kernel UPGRADE

Affected: <= 5.9 · 5.10 rc1 · 5.10 rc2

Fixed in: newer than 5.9

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.

debian debian linux MITIGATE

Affected: 9.0

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.

starwindsoftware command center MITIGATE

Affected: all versions

Fixed in: no fixed release known

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy command-center || rpm -q command-center || command-center --version

No fixed or unaffected release known

Apply the vendor mitigation from the advisory, disable the affected feature, or restrict network access.

starwindsoftware starwind hyperconverged appliance MITIGATE

Affected: all versions

Fixed in: no fixed release known

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy starwind-hyperconverged-appliance || rpm -q starwind-hyperconverged-appliance || starwind-hyperconverged-appliance --version

No fixed or unaffected release known

Apply the vendor mitigation from the advisory, disable the affected feature, or restrict network access.

starwindsoftware starwind san \& nas DOWNGRADE

Affected: v8r12

Fixed in: no fixed release known

Safe to downgrade to: a release before v8r12

1. Check installed version

apt-cache policy starwind-san--nas || rpm -q starwind-san--nas || starwind-san--nas --version

2. No fixed release: DOWNGRADE to a release before v8r12 (Debian / Ubuntu)

apt-cache madison starwind-san--nas sudo apt install starwind-san--nas=<VERSION_BEFORE_v8r12> sudo apt-mark hold starwind-san--nas

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

dnf --showduplicates list starwind-san--nas sudo dnf downgrade starwind-san--nas-<VERSION_BEFORE_v8r12> sudo dnf versionlock add starwind-san--nas

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.

starwindsoftware starwind virtual san DOWNGRADE

Affected: v8 build14398

Fixed in: no fixed release known

Safe to downgrade to: a release before v8

1. Check installed version

apt-cache policy starwind-virtual-san || rpm -q starwind-virtual-san || starwind-virtual-san --version

2. No fixed release: DOWNGRADE to a release before v8 (Debian / Ubuntu)

apt-cache madison starwind-virtual-san sudo apt install starwind-virtual-san=<VERSION_BEFORE_v8> sudo apt-mark hold starwind-virtual-san

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

dnf --showduplicates list starwind-virtual-san sudo dnf downgrade starwind-virtual-san-<VERSION_BEFORE_v8> sudo dnf versionlock add starwind-virtual-san

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-2020-25704?

linux kernel: upgrade to newer than 5.9; debian linux: mitigate or apply the listed mitigation; command center: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2020-25704 being exploited?

CVE-2020-25704 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-2020-25704 affect?

CVE-2020-25704 affects linux kernel, debian linux, command center. Severity is medium (CVSS 5.5). A flaw memory leak in the Linux kernel performance monitoring subsystem was found in the way if using PERF_EVENT_IOC_SET_FILTER. A local user could use this flaw to starve the resources causing denial of service.

How urgent is CVE-2020-25704?

Priority 31/100. On your watchlist

Software pages

Linux kernel vulnerabilities · Debian vulnerabilities

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References

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