CVE-2004-0961: Memory leak in FreeRADIUS before 1.0.1 allows remote attackers to cause a denial of service (memory exhaustion

This month

MEDIUM 5.0WATCHLISTDOWNGRADEMITIGATEMITIGATE

CVE-2004-0961 is a medium-severity flaw (CVSS 5.0) affecting freeradius, enterprise linux, fedora core. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Memory leak in FreeRADIUS before 1.0.1 allows remote attackers to cause a denial of service (memory exhaustion) via a series of Access-Request packets with (1) Ascend-Send-Secret, (2) Ascend-Recv-Secret, or (3) Tunnel-Password attributes.

Why this priority

On your watchlist

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

Risk facts

CVSS score	5.0 (Medium)
EPSS exploit chance	3.3% (top 12%)
CISA exploited list	No
Published	2005-02-09
Last modified	2026-06-16

Publisher (CNA): MITRE · Vendor: freeradius · redhat

Last updated 2026-06-16 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2005-02-09 05:00 UTCPublished CVE record published
2026-06-16 22:06 UTCUpdated Record last modified

freeradius freeradius DOWNGRADE

Affected: 0.2 · 0.3 · 0.4 · 0.5 · 0.8 · 0.8.1 · 0.9 · 0.9.1

Fixed in: no fixed release known

Safe to downgrade to: a release before 0.2

1. Check installed version

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

2. No fixed release: DOWNGRADE to a release before 0.2 (Debian / Ubuntu)

apt-cache madison freeradius sudo apt install freeradius=<VERSION_BEFORE_0.2> sudo apt-mark hold freeradius

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

dnf --showduplicates list freeradius sudo dnf downgrade freeradius-<VERSION_BEFORE_0.2> sudo dnf versionlock add freeradius

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.

redhat enterprise linux MITIGATE

Affected: 3.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 3.0

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.

redhat fedora core MITIGATE

Affected: core_2.0

Fixed in: no fixed release known

Safe to downgrade to: a release before core_2.0

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.

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-2004-0961?

freeradius: downgrade or apply the listed mitigation; enterprise linux: mitigate or apply the listed mitigation; fedora core: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2004-0961 being exploited?

CVE-2004-0961 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-2004-0961 affect?

CVE-2004-0961 affects freeradius, enterprise linux, fedora core. Severity is medium (CVSS 5.0). Memory leak in FreeRADIUS before 1.0.1 allows remote attackers to cause a denial of service (memory exhaustion) via a series of Access-Request packets with (1) Ascend-Send-Secret, (2) Ascend-Recv-Secret, or (3) Tunnel-Password attributes.

How urgent is CVE-2004-0961?

Priority 45/100. On your watchlist

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References

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