CVE-2017-7494: Samba Remote Code Execution Vulnerability

Q: How do I fix CVE-2017-7494?

samba: upgrade to 4.4.0, 4.4.14, 4.5.10, 4.6.4; debian linux: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Q: Is CVE-2017-7494 being exploited?

Yes. CVE-2017-7494 is on the CISA Known Exploited Vulnerabilities list, so treat it as patch-now.

Q: What does CVE-2017-7494 affect?

CVE-2017-7494 affects samba, debian linux. Severity is critical (CVSS 9.8). Samba since version 3.5.0 and before 4.6.4, 4.5.10 and 4.4.14 is vulnerable to remote code execution vulnerability, allowing a malicious client to upload a shared library to a writable share, and then cause the server to load and execute it

Q: How urgent is CVE-2017-7494?

Priority 100/100. Critical severity; EPSS top 1%: very likely to be exploited; Exploited in the wild (CISA KEV); Used in ransomware campaigns; Public exploit reference; CISA SSVC: automatable with total technical impact; Remotely exploitable, no login, no user action; On your watchlist

100

Patch now

CRITICAL 9.8EXPLOITEDREMOTEWATCHLISTUPGRADEMITIGATE

CVE-2017-7494 is a critical-severity flaw (CVSS 9.8) affecting samba, debian linux, reported as exploited in the wild. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Samba since version 3.5.0 and before 4.6.4, 4.5.10 and 4.4.14 is vulnerable to remote code execution vulnerability, allowing a malicious client to upload a shared library to a writable share, and then cause the server to load and execute it.

Why this priority

Critical severity
EPSS top 1%: very likely to be exploited
Exploited in the wild (CISA KEV)
Used in ransomware campaigns
Public exploit reference
CISA SSVC: automatable with total technical impact
Remotely exploitable, no login, no user action
On your watchlist

A fixed release or distro patch exists.

Risk facts

CVSS score	9.8 (Critical)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	99.4% (top 1%)
CISA exploited list	Yes, fix due 2023-04-20, used in ransomware
Weakness	CWE-94
Published	2017-05-30
Last modified	2026-06-17

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

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

Am I affected?

Timeline

2017-05-30 18:29 UTCPublished CVE record published
2023-03-30Exploited Added to the CISA Known Exploited Vulnerabilities list
2023-04-20Deadline CISA due date for US federal agencies to patch
2026-06-17 01:24 UTCUpdated Record last modified

samba samba UPGRADE

Affected: >= 3.5.0 and < 4.4.0 · >= 4.4.0 and < 4.4.14 · >= 4.5.0 and < 4.5.10 · >= 4.6.0 and < 4.6.4

Fixed in: 4.4.0, 4.4.14, 4.5.10, 4.6.4

Safe to downgrade to: a release before 3.5.0

1. Check installed version

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

2. UPGRADE to 4.4.0 (Debian / Ubuntu)

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

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade samba

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 3.5.0 (Debian / Ubuntu)

apt-cache madison samba sudo apt install samba=<VERSION_BEFORE_3.5.0> sudo apt-mark hold samba

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

dnf --showduplicates list samba sudo dnf downgrade samba-<VERSION_BEFORE_3.5.0> sudo dnf versionlock add samba

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.

debian debian linux MITIGATE

Affected: 8.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 8.0

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.

Exact fixes by distribution

A distro patch exists: prefer upgrading over downgrading.

Fedora 46 · root · FIXED · 6.40.04-7.fc46 · FEDORA-2026-7329868400 · source

sudo dnf upgrade --advisory=FEDORA-2026-7329868400

Debian 12 · samba · FIXED · 2:4.5.8+dfsg-2

sudo apt update && sudo apt install --only-upgrade samba dpkg --compare-versions "$(dpkg-query -W -f='${Version}' samba)" ge "2:4.5.8+dfsg-2" && echo PATCHED || echo STILL-VULNERABLE

Debian 13 · samba · FIXED · 2:4.5.8+dfsg-2

sudo apt update && sudo apt install --only-upgrade samba dpkg --compare-versions "$(dpkg-query -W -f='${Version}' samba)" ge "2:4.5.8+dfsg-2" && echo PATCHED || echo STILL-VULNERABLE

RHEL 5 Extended Lifecycle Support · samba3x · FIXED · samba3x-3.6.23-14.el5_11

sudo dnf upgrade --advisory=RHSA-2017:1272 rpm -q samba3x

RHEL 6 · samba · FIXED · samba-3.6.23-43.el6_9

sudo dnf upgrade --advisory=RHSA-2017:1270 rpm -q samba

RHEL 6 · samba4 · FIXED · samba4-4.2.10-10.el6_9

sudo dnf upgrade --advisory=RHSA-2017:1271 rpm -q samba4

RHEL 6.2 Advanced Update Support · samba · FIXED · samba-3.6.23-32.el6_2

sudo dnf upgrade --advisory=RHSA-2017:1390 rpm -q samba

RHEL 6.4 Advanced Update Support · samba · FIXED · samba-3.6.23-32.el6_4

sudo dnf upgrade --advisory=RHSA-2017:1390 rpm -q samba

Amazon Linux 1 · see advisory · FIXED · ALAS-2017-834 · source

sudo yum update --advisory=ALAS-2017-834

Public exploits and detection

Public code exists for this CVE. Treat unpatched systems as at risk, and only run PoCs in a lab.

GitHub PoC: opsxcq/exploit-CVE-2017-7494 (380 stars)
GitHub PoC: joxeankoret/CVE-2017-7494 (259 stars)
GitHub PoC: betab0t/cve-2017-7494 (181 stars)
Write-up: h20566.www2.hpe.com/hpsc/doc/public/display?docLocale=en_US&docId=emr_na-hpesbns03755en_us
Write-up: www.exploit-db.com/exploits/42060/
Exploit-DB: Samba 3.5.0 - Remote Code Execution
Exploit-DB: Samba 3.5.0 < 4.4.14/4.5.10/4.6.4 - 'is_known_pipename()' Arbitrary Module Load (Metasploit)
Metasploit: Samba is_known_pipename() Arbitrary Module Load

Advisories and coverage

Official advisories

F5 Security Advisories: SambaCry: The Linux Sequel to WannaCry 2017-05-26

Verify at the official source NVD · CVE Program · CISA KEV catalog · 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-2017-7494?

samba: upgrade to 4.4.0, 4.4.14, 4.5.10, 4.6.4; debian linux: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2017-7494 being exploited?

Yes. CVE-2017-7494 is on the CISA Known Exploited Vulnerabilities list, so treat it as patch-now.

What does CVE-2017-7494 affect?

CVE-2017-7494 affects samba, debian linux. Severity is critical (CVSS 9.8). Samba since version 3.5.0 and before 4.6.4, 4.5.10 and 4.4.14 is vulnerable to remote code execution vulnerability, allowing a malicious client to upload a shared library to a writable share, and then cause the server to load and execute it

How urgent is CVE-2017-7494?

Priority 100/100. Critical severity; EPSS top 1%: very likely to be exploited; Exploited in the wild (CISA KEV); Used in ransomware campaigns; Public exploit reference; CISA SSVC: automatable with total technical impact; Remotely exploitable, no login, no user action; On your watchlist

Software pages

Debian vulnerabilities · Samba vulnerabilities

Related CVEs

CVE-2026-1933 HIGH 7.1 DOWNGRADE UPGRADE A flaw was found in Samba’s handling of NTFS-style reparse points on shares configured with read only = yes
CVE-2026-4408 CRITICAL 9.0 DOWNGRADE UPGRADE A flaw was found in Samba
CVE-2026-3012 HIGH 8.0 DOWNGRADE UPGRADE A flaw was found in Samba’s certificate auto-enrollment Group Policy handling
CVE-2026-58224 MEDIUM 6.5 UPGRADE MITIGATE A flaw was found in Samba's CTDB, the clustered database service used by Samba
CVE-2026-2340 MEDIUM 6.5 DOWNGRADE DOWNGRADE A flaw was found in Samba’s vfs_worm module

References

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