CVE-2019-13456: In FreeRADIUS 3.0 through 3.0.19, on average 1 in every 2048 EAP-pwd handshakes fails because the password ele

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MEDIUM 6.5WATCHLISTUPGRADEMITIGATEMITIGATE

CVE-2019-13456 is a medium-severity flaw (CVSS 6.5) affecting freeradius, enterprise linux, leap. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

In FreeRADIUS 3.0 through 3.0.19, on average 1 in every 2048 EAP-pwd handshakes fails because the password element cannot be found within 10 iterations of the hunting and pecking loop. This leaks information that an attacker can use to recover the password of any user. This information leakage is similar to the "Dragonblood" attack and CVE-2019-9494.

Why this priority

Public exploit reference
On your watchlist

A fixed release or distro patch exists.

Risk facts

CVSS score	6.5 (Medium)
Attack vector	Adjacent network
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	1.8% (top 22%)
CISA exploited list	No
Weakness	CWE-203
Published	2019-12-03
Last modified	2026-06-17

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

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

Am I affected?

Timeline

2019-12-03 20:15 UTCPublished CVE record published
2026-06-17 02:16 UTCUpdated Record last modified

freeradius freeradius UPGRADE

Affected: >= 3.0.0 and <= 3.0.19

Fixed in: newer than 3.0.19

Safe to downgrade to: a release before 3.0.0

1. Check installed version

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

2. UPGRADE to newer than 3.0.19 (Debian / Ubuntu)

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

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade freeradius

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 3.0.0 (Debian / Ubuntu)

apt-cache madison freeradius sudo apt install freeradius=<VERSION_BEFORE_3.0.0> sudo apt-mark hold freeradius

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

dnf --showduplicates list freeradius sudo dnf downgrade freeradius-<VERSION_BEFORE_3.0.0> 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: 7.0 · 8.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 7.0

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.

opensuse leap MITIGATE

Affected: 15.1

Fixed in: no fixed release known

Safe to downgrade to: a release before 15.1

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-2019-13456?

freeradius: upgrade to newer than 3.0.19; enterprise linux: mitigate or apply the listed mitigation; leap: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2019-13456 being exploited?

CVE-2019-13456 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-2019-13456 affect?

CVE-2019-13456 affects freeradius, enterprise linux, leap. Severity is medium (CVSS 6.5). In FreeRADIUS 3.0 through 3.0.19, on average 1 in every 2048 EAP-pwd handshakes fails because the password element cannot be found within 10 iterations of the hunting and pecking loop. This leaks information that an attacker can use to reco

How urgent is CVE-2019-13456?

Priority 52/100. Public exploit reference; On your watchlist

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References

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