CVE-2023-4154 [High] | Out-of-bounds Write in Samba

A design flaw was found in Samba's DirSync control implementation, which exposes passwords and secrets in Active Directory to privileged users and Read-Only Domain Controllers (RODCs). This flaw allows RODCs and users possessing the GET_CHANGES right to access all attributes, including sensitive secrets and passwords. Even in a default setup, RODC DC accounts, which should only replicate some passwords, can gain access to all domain secrets, including the vital krbtgt, effectively eliminating the RODC / DC distinction. Furthermore, the vulnerability fails to account for error conditions (fail open), like out-of-memory situations, potentially granting access to secret attributes, even under low-privileged attacker influence.

#	Date	Old EPSS score	New EPSS score	Delta (New - Old)
1	2026-06-15	0.40%	1.15%	+0.75%
2	2026-04-15	0.52%	0.40%	-0.12%
3	2026-04-14	—	0.52%	—

Date

Old EPSS score

New EPSS score

Delta (New - Old)

2026-06-15

0.40%

1.15%

+0.75%

2026-04-15

0.52%

0.40%

-0.12%

2026-04-14

—

0.52%

—

Base score	Version	Severity	Vector	Exploitability	Impact	Score source
7.5	3.1	HIGH	`CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H` Click to expand Attack vector (AV:N) Could be attacked over the internet or any normal routed network—not just someone sitting at the machine. Attack complexity (AC:H) Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work. Privileges required (PR:L) A normal user session is enough; they don’t have to be admin. User interaction (UI:N) Nobody has to click “OK” or open a trap file; it can work without a victim helping. Scope (S:U) Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems. Confidentiality (C:H) Serious risk that confidential data gets exposed in a big way. Integrity (I:H) They could widely tamper with or forge data—trust in the data is badly hurt. Availability (A:H) Could take the service down hard or make it unusable for people who depend on it.	1.6	5.9	[email protected]
6.5	3.1	MEDIUM	`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N` Click to expand Attack vector (AV:N) Could be attacked over the internet or any normal routed network—not just someone sitting at the machine. Attack complexity (AC:L) Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup. Privileges required (PR:L) A normal user session is enough; they don’t have to be admin. User interaction (UI:N) Nobody has to click “OK” or open a trap file; it can work without a victim helping. Scope (S:U) Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems. Confidentiality (C:H) Serious risk that confidential data gets exposed in a big way. Integrity (I:N) Data isn’t meaningfully altered or forged. Availability (A:N) Service keeps running; no real outage angle.	2.8	3.6	[email protected]

Base score

Version

Severity

Vector

Exploitability

Impact

Score source

7.5

3.1

HIGH

CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H Click to expand

Attack vector (AV:N): Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:H): Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:L): A normal user session is enough; they don’t have to be admin.
User interaction (UI:N): Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U): Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H): Serious risk that confidential data gets exposed in a big way.
Integrity (I:H): They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H): Could take the service down hard or make it unusable for people who depend on it.

1.6

5.9

[email protected]

6.5

3.1

MEDIUM

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N Click to expand

Attack vector (AV:N): Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L): Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L): A normal user session is enough; they don’t have to be admin.
User interaction (UI:N): Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U): Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H): Serious risk that confidential data gets exposed in a big way.
Integrity (I:N): Data isn’t meaningfully altered or forged.
Availability (A:N): Service keeps running; no real outage angle.

2.8

3.6

[email protected]

OS Trackers for CVE-2023-4154

vendor	priority	summary	link
`alpine`	—	CVE-2023-4154: 1 source package rows (samba); 155 state rows across 7 repos (3.17-main, 3.18-main, 3.19-main, 3.20-main, 3.21-main, 3.22-main, edge-main); fixed 6, open 149.	https://security.alpinelinux.org/vuln/CVE-2023-4154
`debian`	not yet assigned	CVE-2023-4154 not yet assigned priority: Debian including 1 source packages (samba), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 4, open 1.	https://security-tracker.debian.org/tracker/CVE-2023-4154
`gentoo`	high	CVE-2023-4154: 1 GLSA(s) (202402-28), 1 atom(s) (net-fs/samba); latest impact high.	https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2023-4154
`redhat`	medium	—	https://access.redhat.com/security/cve/CVE-2023-4154
`suse`	high	—	https://www.suse.com/security/cve/CVE-2023-4154/
`ubuntu`	medium	CVE-2023-4154 medium priority: Ubuntu including 1 source packages (samba), 12 status rows across 12 suites (bionic, focal, jammy, lunar, mantic, noble, oracular, plucky, questing, trusty, upstream, xenial): released 8, needs-triage 4.	https://ubuntu.com/security/CVE-2023-4154

Affected software / configurations for CVE-2023-4154

Vendor	Product	Version	Raw CPE
samba	samba	>= 4.0.0, < 4.17.12	cpe:2.3:a:samba:samba::::::::
samba	samba	>= 4.18.0, < 4.18.8	cpe:2.3:a:samba:samba::::::::
samba	samba	>= 4.19.0, < 4.19.1	cpe:2.3:a:samba:samba::::::::

References for CVE-2023-4154

URL	Tags
https://access.redhat.com/security/cve/CVE-2023-4154	Third Party Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=2241883	Issue Tracking
https://bugzilla.samba.org/show_bug.cgi?id=15424	Issue Tracking Patch
https://security.netapp.com/advisory/ntap-20231124-0002/
https://www.samba.org/samba/security/CVE-2023-4154.html	Vendor Advisory

URL

CVE-2023-4154 | Samba: ad dc password exposure to privileged users and rodcs

Exploit prediction scoring system (EPSS) score for CVE-2023-4154

Common vulnerability scoring system (CVSS) metrics for CVE-2023-4154

Weakness enumeration for CVE-2023-4154

OS Trackers for CVE-2023-4154

Affected software / configurations for CVE-2023-4154

References for CVE-2023-4154