Samba: infinite loop in mdssvc rpc service for spotlight
An infinite loop vulnerability was found in Samba's mdssvc RPC service for Spotlight. When parsing Spotlight mdssvc RPC packets sent by the client, the core unmarshalling function sl_unpack_loop() did not validate a field in the network packet that contains the count of elements in an array-like structure. By passing 0 as the count value, the attacked function will run in an endless loop consuming 100% CPU. This flaw allows an attacker to issue a malformed RPC request, triggering an infinite loop, resulting in a denial of service condition.
- Published
- Jul 20, 2023
- Updated
- Jun 17, 2026
- EPSS
- 62.4% · 99th percentile
- CWE
- CWE-835
Sign in to follow · You’ll be notified if a followed record enters KEV, gets an exploit or is updated.
Report tools
Action score
49
Plan
Add it to your regular patch cycle.
- CVSS
- 30 / 40 · 7.5 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 19 / 30 · 62.4%
CNA vs NVD score
- NVD
- 7.5
- CNA · redhat
- 7.5
- agree
The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.
Affected systems
| Vendor | Product | CPE |
|---|---|---|
| samba | samba | cpe:2.3:a:samba:samba |
| fedoraproject | fedora | cpe:2.3:o:fedoraproject:fedora |
| redhat | enterprise linux | cpe:2.3:o:redhat:enterprise_linux |
| debian | debian linux | cpe:2.3:o:debian:debian_linux |
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- debian debian linux11.0
- debian debian linux12.0
- fedoraproject fedora37
- fedoraproject fedora38
- redhat enterprise linux8.0
- redhat enterprise linux9.0
- samba sambabefore 4.16.11
- samba samba4.18.0 and later · before 4.18.5
- samba samba4.17.0 and later · before 4.17.10
Versions reported by the vendor
Affected version ranges reported by the assigning authority (redhat). Independent of NVD's CPE analysis and usually ahead of it.
Red Hat Red Hat Enterprise Linux 6
- all versionsunknown
- all versionsunknown
Red Hat Red Hat Enterprise Linux 7
- all versionsunknown
Red Hat Red Hat Enterprise Linux 8
- 0:4.18.6-1.el8 and laternot affected · rpm
- 0:4.18.6-1.el8 and laternot affected · rpm
Red Hat Red Hat Enterprise Linux 8.6 Extended Update Support
- 0:4.15.5-15.el8_6 and laternot affected · rpm
Red Hat Red Hat Enterprise Linux 8.8 Extended Update Support
- 0:4.17.5-5.el8_8 and laternot affected · rpm
Red Hat Red Hat Enterprise Linux 9
- 0:4.18.6-100.el9 and laternot affected · rpm
- 0:4.18.6-100.el9 and laternot affected · rpm
Red Hat Red Hat Enterprise Linux 9.2 Extended Update Support
- 0:4.17.5-105.el9_2 and laternot affected · rpm
Red Hat Red Hat Storage 3
- all versionsunknown
Red Hat Red Hat Virtualization 4 for Red Hat Enterprise Linux 8
- 0:4.15.5-15.el8_6 and laternot affected · rpm
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| AlmaLinux:8 | ctdb | before 4.18.6-1.el8 | 4.18.6-1.el8 |
| AlmaLinux:8 | libnetapi | before 4.18.6-1.el8 | 4.18.6-1.el8 |
| AlmaLinux:8 | libnetapi-devel | before 4.18.6-1.el8 | 4.18.6-1.el8 |
| AlmaLinux:8 | libsmbclient | before 4.18.6-1.el8 | 4.18.6-1.el8 |
| AlmaLinux:8 | libsmbclient-devel | before 4.18.6-1.el8 | 4.18.6-1.el8 |
| AlmaLinux:8 | libwbclient | before 4.18.6-1.el8 | 4.18.6-1.el8 |
| AlmaLinux:8 | libwbclient-devel | before 4.18.6-1.el8 | 4.18.6-1.el8 |
| AlmaLinux:8 | python3-samba | before 4.18.6-1.el8 | 4.18.6-1.el8 |
| AlmaLinux:8 | python3-samba-dc | before 4.18.6-1.el8 | 4.18.6-1.el8 |
| AlmaLinux:8 | python3-samba-devel | before 4.18.6-1.el8 | 4.18.6-1.el8 |
| AlmaLinux:8 | python3-samba-test | before 4.18.6-1.el8 | 4.18.6-1.el8 |
| AlmaLinux:8 | samba | before 4.18.6-1.el8 | 4.18.6-1.el8 |
| AlmaLinux:8 | samba-client | before 4.18.6-1.el8 | 4.18.6-1.el8 |
| AlmaLinux:8 | samba-client-libs | before 4.18.6-1.el8 | 4.18.6-1.el8 |
| AlmaLinux:8 | samba-common | before 4.18.6-1.el8 | 4.18.6-1.el8 |
| AlmaLinux:8 | samba-common-libs | before 4.18.6-1.el8 | 4.18.6-1.el8 |
| AlmaLinux:8 | samba-common-tools | before 4.18.6-1.el8 | 4.18.6-1.el8 |
| AlmaLinux:8 | samba-dc-libs | before 4.18.6-1.el8 | 4.18.6-1.el8 |
| AlmaLinux:8 | samba-dcerpc | before 4.18.6-1.el8 | 4.18.6-1.el8 |
| AlmaLinux:8 | samba-devel | before 4.18.6-1.el8 | 4.18.6-1.el8 |
| AlmaLinux:8 | samba-krb5-printing | before 4.18.6-1.el8 | 4.18.6-1.el8 |
| AlmaLinux:8 | samba-ldb-ldap-modules | before 4.18.6-1.el8 | 4.18.6-1.el8 |
| AlmaLinux:8 | samba-libs | before 4.18.6-1.el8 | 4.18.6-1.el8 |
| AlmaLinux:8 | samba-pidl | before 4.18.6-1.el8 | 4.18.6-1.el8 |
+96
Same product
samba: all recordsOther highest-scoring records for the same primary product.
- CVE-2017-7494Samba 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 cliKEV99Now
- CVE-2015-0240The Netlogon server implementation in smbd in Samba 3.5.x and 3.6.x before 3.6.25, 4.0.x before 4.0.25, 4.1.x before 4.1.17, and 4.2.x befor66This week
- CVE-2003-0085Buffer overflow in the SMB/CIFS packet fragment re-assembly code for SMB daemon (smbd) in Samba before 2.2.8, and Samba-TNG before 0.3.1, al66This week
- CVE-2003-0201Buffer overflow in the call_trans2open function in trans2.c for Samba 2.2.x before 2.2.8a, 2.0.10 and earlier 2.0.x versions, and Samba-TNG 65This week
- CVE-2007-2446Multiple heap-based buffer overflows in the NDR parsing in smbd in Samba 3.0.0 through 3.0.25rc3 allow remote attackers to execute arbitrary63This week
- CVE-2012-1182The RPC code generator in Samba 3.x before 3.4.16, 3.5.x before 3.5.14, and 3.6.x before 3.6.4 does not implement validation of an array len62This week
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| AlmaLinux:ctdb | 4.18.6-100.el9 · AlmaLinux:9 | Package registry (OSV) |
| AlmaLinux:libnetapi | 4.18.6-100.el9 · AlmaLinux:9 | Package registry (OSV) |
| AlmaLinux:libnetapi-devel | 4.18.6-100.el9 · AlmaLinux:9 | Package registry (OSV) |
| AlmaLinux:libsmbclient | 4.18.6-100.el9 · AlmaLinux:9 | Package registry (OSV) |
| AlmaLinux:libsmbclient-devel | 4.18.6-100.el9 · AlmaLinux:9 | Package registry (OSV) |
| AlmaLinux:libwbclient | 4.18.6-100.el9 · AlmaLinux:9 | Package registry (OSV) |
| AlmaLinux:libwbclient-devel | 4.18.6-100.el9 · AlmaLinux:9 | Package registry (OSV) |
| AlmaLinux:python3-samba | 4.18.6-100.el9 · AlmaLinux:9 | Package registry (OSV) |
| AlmaLinux:python3-samba-dc | 4.18.6-100.el9 · AlmaLinux:9 | Package registry (OSV) |
| AlmaLinux:python3-samba-devel | 4.18.6-100.el9 · AlmaLinux:9 | Package registry (OSV) |
| AlmaLinux:python3-samba-test | 4.18.6-100.el9 · AlmaLinux:9 | Package registry (OSV) |
| AlmaLinux:samba | 4.18.6-100.el9 · AlmaLinux:9 | Package registry (OSV) |
| Debian:samba | 2:4.17.10+dfsg-0+deb12u1 · Debian:12 | Package registry (OSV) |
| openSUSE:samba | 4.17.9+git.367.dae41ffdd1f-150500.3.5.1 · openSUSE:Leap 15.5 | Package registry (OSV) |
| Red Hat:ctdb-debuginfo | 0:4.18.6-100.el9 · Red Hat:enterprise_linux:9::appstream | Package registry (OSV) |
| Red Hat:libnetapi-debuginfo | 0:4.18.6-100.el9 · Red Hat:enterprise_linux:9::appstream | Package registry (OSV) |
| Red Hat:libsmbclient-debuginfo | 0:4.18.6-100.el9 · Red Hat:enterprise_linux:9::appstream | Package registry (OSV) |
| Red Hat:libwbclient-debuginfo | 0:4.18.6-100.el9 · Red Hat:enterprise_linux:9::appstream | Package registry (OSV) |
| Red Hat:python3-samba-dc-debuginfo | 0:4.18.6-100.el9 · Red Hat:enterprise_linux:9::appstream | Package registry (OSV) |
| Red Hat:python3-samba-debuginfo | 0:4.18.6-100.el9 · Red Hat:enterprise_linux:9::appstream | Package registry (OSV) |
| Red Hat:samba-client | 0:4.18.6-100.el9 · Red Hat:enterprise_linux:9::appstream | Package registry (OSV) |
| Red Hat:samba-client-debuginfo | 0:4.18.6-100.el9 · Red Hat:enterprise_linux:9::appstream | Package registry (OSV) |
| Red Hat:samba-client-libs-debuginfo | 0:4.18.6-100.el9 · Red Hat:enterprise_linux:9::appstream | Package registry (OSV) |
| Red Hat:samba-common-libs-debuginfo | 0:4.18.6-100.el9 · Red Hat:enterprise_linux:9::appstream | Package registry (OSV) |
| Red Hat:samba-common-tools-debuginfo | 0:4.18.6-100.el9 · Red Hat:enterprise_linux:9::appstream | Package registry (OSV) |
| Red Hat:samba-dc-libs-debuginfo | 0:4.18.6-100.el9 · Red Hat:enterprise_linux:9::appstream | Package registry (OSV) |
| Rocky Linux:evolution-mapi | 0:3.28.3-8.el8 · Rocky Linux:8 | Package registry (OSV) |
| Rocky Linux:openchange | 0:2.3-32.el8 · Rocky Linux:8 | Package registry (OSV) |
| SUSE:samba | 4.15.13+git.621.c8ae836ff82-3.85.1 · SUSE:Linux Enterprise High Availability Extension 12 SP5 | Package registry (OSV) |
| SUSE:samba | 4.17.9+git.367.dae41ffdd1f-150500.3.5.1 · SUSE:Linux Enterprise Module for Basesystem 15 SP5 | Package registry (OSV) |
Exploit status
No known public exploit
No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
No dated events beyond publication.
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
No commit or PR link among the references.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
No credits in the CNA record.
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
No nightly-computed relations.
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
—
Bug bounty scope
No known public program.
Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).
Technical details
Attack conditions
- Anyone who can reach it over the internet can trigger it.
- No account or password is required.
- No user action is required.
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- none
- Integrity
- none
- Availability
- high · the service can be disrupted
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- None
- Integrity impact
- None
- Availability impact
- High
Weakness class (CWE)
CWE-835 · Loop with Unreachable Exit Condition ('Infinite Loop')CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
nvd-primary
Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
MITRE has no CAPEC/ATT&CK mapping for this CWE.
Noroxi analysis
No Noroxi analysis for this record yet
We don't hand-write analysis for all 385,000+ vulnerabilities; that wouldn't be honest. For notable, high-impact vulnerabilities our team writes the mechanism, detection and remediation steps.
We use this product, ask for helpChange log
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
- access.redhat.com/errata/RHSA-2023:6667
- access.redhat.com/errata/RHSA-2023:7139
- access.redhat.com/errata/RHSA-2024:0423
- access.redhat.com/errata/RHSA-2024:0580
- access.redhat.com/errata/RHSA-2024:4101
- access.redhat.com/security/cve/CVE-2023-34966
- bugzilla.redhat.com/show_bug.cgi?id=2222793
- www.samba.org/samba/security/CVE-2023-34966
- lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/BPCSGND7LO467AJGR5DYBGZLTCGTOBCC/
- lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/OT74M42E6C36W7PQVY3OS4ZM7DVYB64Z/
- security.netapp.com/advisory/ntap-20230731-0010/
- www.debian.org/security/2023/dsa-5477
Vendor advisories and official records. Exploit/PoC links are deliberately left out.