CVE-2020-15396: In HylaFAX+ through 7.0.2 and HylaFAX Enterprise, the faxsetup utility calls chown on files in user-owned dire

This month

HIGH 7.8UPGRADEMITIGATEMITIGATE

CVE-2020-15396 is a high-severity flaw (CVSS 7.8) affecting hylafax\+, hylafax enterprise, fedora. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

In HylaFAX+ through 7.0.2 and HylaFAX Enterprise, the faxsetup utility calls chown on files in user-owned directories. By winning a race, a local attacker could use this to escalate his privileges to root.

Why this priority

High severity
Public exploit reference

A fixed release or distro patch exists.

Risk facts

CVSS score	7.8 (High)
Attack vector	Local
Attack complexity	Low
Privileges needed	Low
User interaction	None
EPSS exploit chance	0.4% (top 67%)
CISA exploited list	No
Weakness	CWE-362
Published	2020-06-30
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: fedoraproject · hylafax\+ project · ifax · opensuse

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

Am I affected?

Timeline

2020-06-30 12:15 UTCPublished CVE record published
2026-06-17 02:56 UTCUpdated Record last modified

hylafax\+ project hylafax\+ UPGRADE

Affected: <= 7.0.2

Fixed in: newer than 7.0.2

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy hylafax+ || rpm -q hylafax+ || hylafax+ --version

2. UPGRADE to newer than 7.0.2 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade hylafax+

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade hylafax+

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

ifax hylafax enterprise 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 hylafax-enterprise || rpm -q hylafax-enterprise || hylafax-enterprise --version

No fixed or unaffected release known

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

fedoraproject fedora MITIGATE

Affected: 31 · 32

Fixed in: no fixed release known

Safe to downgrade to: a release before 31

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 backports sle DOWNGRADE

Affected: 15.0 sp1 · 15.0 sp2

Fixed in: no fixed release known

Safe to downgrade to: a release before 15.0

1. Check installed version

apt-cache policy backports-sle || rpm -q backports-sle || backports-sle --version

2. No fixed release: DOWNGRADE to a release before 15.0 (Debian / Ubuntu)

apt-cache madison backports-sle sudo apt install backports-sle=<VERSION_BEFORE_15.0> sudo apt-mark hold backports-sle

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

dnf --showduplicates list backports-sle sudo dnf downgrade backports-sle-<VERSION_BEFORE_15.0> sudo dnf versionlock add backports-sle

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.

opensuse leap MITIGATE

Affected: 15.1 · 15.2

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-2020-15396?

hylafax\+: upgrade to newer than 7.0.2; hylafax enterprise: mitigate or apply the listed mitigation; fedora: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2020-15396 being exploited?

CVE-2020-15396 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-2020-15396 affect?

CVE-2020-15396 affects hylafax\+, hylafax enterprise, fedora. Severity is high (CVSS 7.8). In HylaFAX+ through 7.0.2 and HylaFAX Enterprise, the faxsetup utility calls chown on files in user-owned directories. By winning a race, a local attacker could use this to escalate his privileges to root.

How urgent is CVE-2020-15396?

Priority 41/100. High severity; Public exploit reference

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References

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