A vulnerability was found in Samba's SMB2 packet signing mechanism. The SMB2 packet signing is not enforced if an admin configured "server signing = required" or for SMB2 connections to Domain Controllers where SMB2 packet signing is mandatory. This flaw allows an attacker to perform attacks, such as a man-in-the-middle attack, by intercepting the network traffic and modifying the SMB2 messages between client and server, affecting the integrity of the data.
CVE-2023-3347
“—” beside the score: it is equal to NVD's CVSS score.
Score 5.9 from GitHub Security Advisory published 2023-07-20. NVD baseline CVSS 5.9; sources differ by 0.0.
- Lower severity and no public exploit yet
A fix is available — apply it.
- CVSS v3
- 5.9
- EG Score
- 5.9MEDIUMmedium confidence
- EG Risk
- 27EG Risk 27/100
EG Risk is EchelonGraph's 0–100 priority score. It fuses impact severity (EG Severity, the CVSS base score, never the KEV-floored or EPSS-lifted EG Score) with real-world exploitation and automatability, under weights EchelonGraph set by hand, so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner.
How it’s computed (value × EchelonGraph’s weight)Severity59% × 45%Impact severity (EG Severity): CVSS 5.9 of 10. Never the KEV-floored or EPSS-lifted EG Score.Exploitation0.4% × 40%FIRST EPSS: the 30-day exploitation probability when EchelonGraph scored this CVE.Automatability0% × 15%CISA's SSVC Automatable value: no (Vulnrichment).SSVC (CISA's decision table, applied by EchelonGraph): Track at every mission impact level.Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE.Action: A fix is available. Apply it within your standard update timelines. - EPSS PROB
- 0.4%
- EPSS %ILE
- 36th
- KEV
- Not listed
What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)
The EG score (5.9): severity, escalated by confirmed exploitation. This CVE's 5.9 is its impact severity (EG Severity), not escalated.
- EG Severity
- 5.9 MEDIUMCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
- EG Likelihood
- 0.4% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-17). FIRST's exploitation probability, not an EchelonGraph model.
- Confirmed exploitation
- None on record (CISA KEV, EG-KEV Tier 1)Reported apart from the likelihood: an observed fact, not a probability.
- EG Priority
- SSVC Track at medium mission impactTrack at every mission impact level.CISA BOD 26-04: 60 days if the affected system is publicly exposed; Fix on system upgrade if it is not.Each input and its source: the SSVC and BOD 26-04 blocks below.
SSVC (CISA's decision table, applied by EchelonGraph)Track at every mission impact level.
A fix is available. Apply it within your standard update timelines.
Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table
BOD 26-04 (CISA's remediation timeline, Table 1)60 days if the affected system is publicly exposed; Fix on system upgrade if it is not.
In CISA KEV no (CISA's KEV catalog) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it
Published
July 20, 2023
Last Modified
December 6, 2024
References (9)
- secalert@redhat · CVE Programhttps://access.redhat.com/errata/RHSA-2023:4325Third Party Advisory
- secalert@redhat · CVE Programhttps://access.redhat.com/errata/RHSA-2023:4328Third Party Advisory
- secalert@redhat · CVE Programhttps://access.redhat.com/security/cve/CVE-2023-3347Third Party Advisory
- secalert@redhat · CVE Programhttps://bugzilla.redhat.com/show_bug.cgi?id=2222792Issue Tracking · Third Party Advisory
- secalert@redhat · CVE Programhttps://www.samba.org/samba/security/CVE-2023-3347.htmlVendor Advisory
- CVE Programhttps://lists.fedoraproject.org/archives/list/[email protected]/message/BPCSGND7LO467AJGR5DYBGZLTCGTOBCC/
- CVE Programhttps://lists.fedoraproject.org/archives/list/[email protected]/message/OT74M42E6C36W7PQVY3OS4ZM7DVYB64Z/
- CVE Programhttps://security.netapp.com/advisory/ntap-20230731-0010/
- CVE Programhttps://www.debian.org/security/2023/dsa-5477
Patch Availability(3)
| Vendor / Ecosystem | Fix (by version range) / Patch | Released | Source |
|---|---|---|---|
| ubuntu | ctdb (2:4.17.7+dfsg-1ubuntu1.1) @ lunar | 2026-05-24 | ubuntu |
| redhat | samba-0:4.17.5-3.el8_8 | 2023-07-31 | redhat |
| redhat | samba-0:4.17.5-103.el9_2 | 2023-07-31 | redhat |
Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.
Affected Packages
(3 across 3 ecosystems)
Debian:12(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| samba | 2:4.17.10+dfsg-0+deb12u1~bpo11+1 ... 2:4.17.9+dfsg-0+deb12u3~bpo11+1 (7 versions) |
| — |
Debian:13(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| samba | — |
| — |
Debian:14(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| samba | — |
| — |
Weakness Classification(2)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
All Vendor Advisories
(3)
Every vendor that published an advisory referencing this CVE — pulled from our cve_vendor_advisories aggregation. Click any row for the vendor's original advisory page.
Data Freshness Timeline
(refreshed 8× in last 7d / 34× in last 30d)
Each row is a time one of our pipelines fetched, updated or re-scored this CVE. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. An arrow marks a change the record states ("CVSS v3 → 9.1"); EPSS and GHSA rows show the values recorded at that time, not what changed (EPSS values are rounded; hover one for the exact figures). Most recent first.
Showing the most recent 85 of 202 refreshes on record for this CVE.
A repeat, a row identical to one the same pipeline wrote less than 10 seconds earlier, is not a separate refresh and is not counted. 15 repeat rows among the latest 100 are merged into the row they repeat. The 117 oldest rows on record are not shown and were not checked, so the counts can still include repeats.
- 2026-10-23 16:29 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-10-22 16:31 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-10-21 16:29 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-10-20 16:30 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-10-19 16:29 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-10-18 16:29 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-10-18 08:00 UTCEG score recompute
- 2026-10-17 16:30 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-10-16 16:36 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-10-15 16:29 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-10-14 16:30 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-10-13 16:30 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-10-13 09:54 UTCOSV refresh
- 2026-10-12 18:26 UTCEG score recompute
- 2026-10-12 16:31 UTCEPSS rescoreEPSS 0.4% · 35th percentile
- 2026-10-11 21:52 UTCEG score recompute
- 2026-10-11 13:45 UTCEPSS rescoreEPSS 0.4% · 35th percentile
- 2026-10-10 19:57 UTCEPSS rescoreEPSS 0.4% · 35th percentile
- 2026-10-09 20:05 UTCEPSS rescoreEPSS 0.4% · 35th percentile
- 2026-10-08 17:06 UTCEPSS rescoreEPSS 0.4% · 35th percentile
- 2026-10-07 23:46 UTCEPSS rescoreEPSS 0.4% · 35th percentile
- 2026-10-06 15:15 UTCEPSS rescoreEPSS 0.4% · 35th percentile
- 2026-10-05 17:41 UTCEPSS rescoreEPSS 0.4% · 35th percentile
- 2026-10-04 23:20 UTCEPSS rescoreEPSS 0.4% · 35th percentile
- 2026-10-03 14:23 UTCEPSS rescoreEPSS 0.4% · 35th percentile
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- 2026-10-01 19:48 UTCEPSS rescoreEPSS 0.4% · 35th percentile
- 2026-09-30 16:24 UTCEG score recompute
- 2026-09-30 15:01 UTCEPSS rescoreEPSS 0.4% · 35th percentile
- 2026-09-29 15:17 UTCEPSS rescoreEPSS 0.4% · 35th percentile
- 2026-09-28 13:49 UTCEPSS rescoreEPSS 0.4% · 35th percentile
- 2026-09-27 13:42 UTCEPSS rescoreEPSS 0.4% · 35th percentile
- 2026-09-26 15:56 UTCEPSS rescoreEPSS 0.4% · 35th percentile
- 2026-09-26 00:22 UTCEPSS rescoreEPSS 0.4% · 35th percentile
- 2026-09-24 14:01 UTCEPSS rescoreEPSS 0.4% · 35th percentile
- 2026-09-23 13:46 UTCEPSS rescoreEPSS 0.4% · 37th percentile
- 2026-09-23 04:02 UTCOSV refresh
- 2026-09-20 20:14 UTCEPSS rescoreEPSS 0.4% · 37th percentile
- 2026-09-18 19:25 UTCEPSS rescoreEPSS 0.4% · 37th percentile
- 2026-09-17 19:25 UTCEPSS rescoreEPSS 0.4% · 37th percentile
- 2026-09-16 14:06 UTCEPSS rescoreEPSS 0.4% · 37th percentile
- 2026-09-16 05:11 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-09-13 16:44 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-09-12 14:58 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-09-11 14:50 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-09-11 09:34 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-09-08 21:58 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-09-07 15:59 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-09-06 13:45 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-09-05 15:26 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-09-04 13:58 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-09-04 05:04 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-09-03 22:59 UTCOSV refresh
- 2026-09-02 14:09 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-09-01 13:51 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-08-30 19:15 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-08-30 01:20 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-08-28 21:39 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-08-27 14:23 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-08-26 14:43 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-08-25 13:46 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-08-23 00:17 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-08-21 23:47 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-08-20 22:53 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-08-19 17:02 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-08-18 13:46 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-08-17 13:45 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-08-17 12:16 UTCOSV refresh
- 2026-08-16 14:54 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-08-16 02:12 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-08-15 01:28 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-08-13 21:58 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-08-12 13:48 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-08-11 13:39 UTCEPSS rescoreEPSS 0.4% · 35th percentile
- 2026-08-09 13:44 UTCEPSS rescoreEPSS 0.4% · 35th percentile
- 2026-08-08 16:35 UTCEPSS rescoreEPSS 0.4% · 35th percentile
- 2026-08-07 16:25 UTCEPSS rescoreEPSS 0.4% · 35th percentile
- 2026-08-06 13:45 UTCEPSS rescoreEPSS 0.4% · 35th percentile
- 2026-08-05 19:15 UTCEPSS rescoreEPSS 0.4% · 35th percentile
- 2026-08-04 15:07 UTCEPSS rescoreEPSS 0.4% · 35th percentile
- 2026-08-03 10:34 UTCEPSS rescoreEPSS 0.4% · 35th percentile
- 2026-08-02 06:45 UTCOSV refresh
- 2026-08-02 02:25 UTCEPSS rescoreEPSS 0.4% · 35th percentile
- 2026-08-01 04:13 UTCEPSS rescoreEPSS 0.4% · 35th percentile
- 2026-07-30 16:26 UTCEPSS rescoreEPSS 0.4% · 35th percentile
- 2026-07-30 01:28 UTCEPSS rescoreEPSS 0.4% · 35th percentile
Related CVEs(same product + same vendor + same CWE)
Same product
10 shownDebian:12:samba
- CVE-2025-10230EG 10.0EPSS p99CRITICAL
- CVE-2020-1472EG 10.0 KEVEPSS p100CRITICAL
- CVE-2015-0240EG 10.0EPSS p100HIGH
- CVE-2012-1182EG 10.0EPSS p99HIGH
- CVE-2007-2446EG 10.0EPSS p100HIGH
- CVE-2004-0882EG 10.0EPSS p97HIGH
- CVE-2004-1154EG 10.0EPSS p96HIGH
- CVE-2004-0600EG 10.0EPSS p98HIGH
- CVE-2003-0196EG 10.0EPSS p98HIGH
- CVE-2003-0201EG 10.0EPSS p100HIGH
Same vendor
4 shownubuntu:USN-6238-1
Frequently asked(5)
What is CVE-2023-3347?
When was CVE-2023-3347 made public?
Is CVE-2023-3347 actively exploited?
What is the CVSS score of CVE-2023-3347?
How do I remediate CVE-2023-3347?
Dependency Blast Radius
See which npm, PyPI, Go, and Maven packages are affected by CVE-2023-3347
Is Your Infrastructure Affected by CVE-2023-3347?
EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.