CVE-2019-3883 [High] | Denial of Service in 389 Directory Server

In 389-ds-base up to version 1.4.1.2, requests are handled by workers threads. Each sockets will be waited by the worker for at most 'ioblocktimeout' seconds. However this timeout applies only for un-encrypted requests. Connections using SSL/TLS are not taking this timeout into account during reads, and may hang longer.An unauthenticated attacker could repeatedly create hanging LDAP requests to hang all the workers, resulting in a Denial of Service.

#	Date	Old EPSS score	New EPSS score	Delta (New - Old)
1	2026-04-27	0.80%	0.87%	+0.08%
2	2026-03-13	0.37%	0.80%	+0.43%
3	2026-01-17	—	0.37%	—

Date

Old EPSS score

New EPSS score

Delta (New - Old)

2026-04-27

0.80%

0.87%

+0.08%

2026-03-13

0.37%

0.80%

+0.43%

2026-01-17

—

0.37%

—

Base score	Version	Severity	Vector	Exploitability	Impact	Score source
7.5	3.1	HIGH	`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/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:L) Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup. Privileges required (PR:N) No account or special rights needed—anonymous or random user is enough. 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:N) Doesn’t really leak secrets in a meaningful way. Integrity (I:N) Data isn’t meaningfully altered or forged. Availability (A:H) Could take the service down hard or make it unusable for people who depend on it.	3.9	3.6	[email protected]
5.3	3.0	MEDIUM	`CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L` 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:N) No account or special rights needed—anonymous or random user is enough. 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:N) Doesn’t really leak secrets in a meaningful way. Integrity (I:N) Data isn’t meaningfully altered or forged. Availability (A:L) Might cause slowdowns, glitches, or partial disruption—not a full brick.	3.9	1.4	[email protected]
5.0	2.0	MEDIUM	`AV:N/AC:L/Au:N/C:N/I:N/A:P` Click to expand Access vector (AV:N) Can be exploited remotely over network reachability. Access complexity (AC:L) Exploitation conditions are straightforward and predictable. Authentication (AU:N) No authentication is required. Confidentiality impact (C:N) No confidentiality impact. Integrity impact (I:N) No integrity impact. Availability impact (A:P) Partial availability impact.	10.0	2.9	[email protected]

Base score

Version

Severity

Vector

Exploitability

Impact

Score source

7.5

3.1

HIGH

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/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:L): Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N): No account or special rights needed—anonymous or random user is enough.
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:N): Doesn’t really leak secrets in a meaningful way.
Integrity (I:N): Data isn’t meaningfully altered or forged.
Availability (A:H): Could take the service down hard or make it unusable for people who depend on it.

3.9

3.6

[email protected]

5.3

3.0

MEDIUM

CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L 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:N): No account or special rights needed—anonymous or random user is enough.
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:N): Doesn’t really leak secrets in a meaningful way.
Integrity (I:N): Data isn’t meaningfully altered or forged.
Availability (A:L): Might cause slowdowns, glitches, or partial disruption—not a full brick.

3.9

1.4

[email protected]

5.0

2.0

MEDIUM

AV:N/AC:L/Au:N/C:N/I:N/A:P Click to expand

Access vector (AV:N): Can be exploited remotely over network reachability.
Access complexity (AC:L): Exploitation conditions are straightforward and predictable.
Authentication (AU:N): No authentication is required.
Confidentiality impact (C:N): No confidentiality impact.
Integrity impact (I:N): No integrity impact.
Availability impact (A:P): Partial availability impact.

10.0

2.9

[email protected]

OS Trackers for CVE-2019-3883

vendor	priority	summary	link
`debian`	not yet assigned	CVE-2019-3883 not yet assigned priority: Debian including 1 source packages (389-ds-base), 4 status rows across 4 suites (bookworm, bullseye, sid, trixie): resolved 4.	https://security-tracker.debian.org/tracker/CVE-2019-3883
`redhat`	medium	—	https://access.redhat.com/security/cve/CVE-2019-3883
`suse`	medium	CVE-2019-3883 severity moderate: SUSE including 33 source package names (389-ds-1.4.0.26~git0.8a2d3de6f-4.14.1, 389-ds-1.4.3.9~git0.3eb8617f6-1.2, …), 35 product×package rows across 9 product lines (SUSE Liberty Linux 7, SUSE Liberty Linux 8, … (9 product lines)): Fixed 35.	https://www.suse.com/security/cve/CVE-2019-3883/
`ubuntu`	medium	CVE-2019-3883 medium priority: Ubuntu including 1 source packages (389-ds-base), 19 status rows across 19 suites (bionic, cosmic, disco, eoan, focal, groovy, hirsute, impish, jammy, kinetic, lunar, mantic, noble, oracular, plucky, questing, trusty, upstream, xenial): not-affected 13, ignored 2, needed 2, DNE 1, needs-triage 1.	https://ubuntu.com/security/CVE-2019-3883

Affected software / configurations for CVE-2019-3883

Vendor	Product	Version	Raw CPE
fedoraproject	389_directory_server	<= 1.4.1.2	cpe:2.3:a:fedoraproject:389_directory_server::::::::
debian	debian_linux	8.0	cpe:2.3:o:debian:debian_linux:8.0:::::::*
redhat	enterprise_linux	6.0	cpe:2.3:o:redhat:enterprise_linux:6.0:::::::*

References for CVE-2019-3883

URL	Tags
https://access.redhat.com/errata/RHSA-2019:1896	Third Party Advisory
https://access.redhat.com/errata/RHSA-2019:3401	Third Party Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2019-3883	Issue Tracking Third Party Advisory
https://lists.debian.org/debian-lts-announce/2019/05/msg00008.html	Mailing List Third Party Advisory
https://lists.debian.org/debian-lts-announce/2023/04/msg00026.html
https://pagure.io/389-ds-base/issue/50329	Issue Tracking Third Party Advisory
https://pagure.io/389-ds-base/pull-request/50331	Third Party Advisory

URL

CVE-2019-3883

Exploit prediction scoring system (EPSS) score for CVE-2019-3883

Common vulnerability scoring system (CVSS) metrics for CVE-2019-3883

Weakness enumeration for CVE-2019-3883

OS Trackers for CVE-2019-3883

Affected software / configurations for CVE-2019-3883

References for CVE-2019-3883