CVE-2021-33833 [Critical] | Out-of-bounds Write in Connection Manager

CVE-2021-33833 is rated High Exploit Risk (86.6/100): CVSS Critical severity, with medium exploitation likelihood (EPSS 2.86%). 1 public exploit reference(s) are indexed (Exploit-DB). EPSS rose +2.71% over the last day, indicating growing attacker interest. Public exploits are available—assess exposure, apply mitigations, and prioritize patching.

EDB-ID	Source	Kind	Published	Link
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#	Date	Old EPSS score	New EPSS score	Delta (New - Old)
1	2026-06-15	0.15%	2.86%	+2.71%
2	2025-11-21	2.04%	0.15%	-1.89%
3	2025-11-18	—	2.04%	—

Date

Old EPSS score

New EPSS score

Delta (New - Old)

2026-06-15

0.15%

2.86%

+2.71%

2025-11-21

2.04%

0.15%

-1.89%

2025-11-18

—

2.04%

—

Base score	Version	Severity	Vector	Exploitability	Impact	Score source
9.8	3.1	CRITICAL	`CVSS:3.1/AV:N/AC:L/PR:N/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: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: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.	3.9	5.9	[email protected]
7.5	2.0	HIGH	`AV:N/AC:L/Au:N/C:P/I:P/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:P) Partial confidentiality impact. Integrity impact (I:P) Partial integrity impact. Availability impact (A:P) Partial availability impact.	10.0	6.4	[email protected]

Base score

Version

Severity

Vector

Exploitability

Impact

Score source

9.8

3.1

CRITICAL

CVSS:3.1/AV:N/AC:L/PR:N/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: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: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.

3.9

5.9

[email protected]

7.5

2.0

HIGH

AV:N/AC:L/Au:N/C:P/I:P/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:P): Partial confidentiality impact.
Integrity impact (I:P): Partial integrity impact.
Availability impact (A:P): Partial availability impact.

10.0

6.4

[email protected]

OS Trackers for CVE-2021-33833

vendor	priority	summary	link
`debian`	not yet assigned	CVE-2021-33833 not yet assigned priority: Debian including 1 source packages (connman), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5.	https://security-tracker.debian.org/tracker/CVE-2021-33833
`gentoo`	normal	CVE-2021-33833: 1 GLSA(s) (202107-29), 1 atom(s) (net-misc/connman); latest impact normal.	https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2021-33833
`suse`	high	CVE-2021-33833 severity important: SUSE including 16 source package names (connman-1.40-2.2, connman-client-1.40-2.2, …), 16 product×package rows across 1 product lines (openSUSE Tumbleweed): Fixed 16.	https://www.suse.com/security/cve/CVE-2021-33833/
`ubuntu`	medium	CVE-2021-33833 medium priority: Ubuntu including 1 source packages (connman), 11 status rows across 11 suites (bionic, focal, groovy, hirsute, impish, jammy, kinetic, lunar, trusty, upstream, xenial): not-affected 4, ignored 3, released 2, DNE 1, needs-triage 1.	https://ubuntu.com/security/CVE-2021-33833

Affected software / configurations for CVE-2021-33833

Vendor	Product	Version	Raw CPE
intel	connection_manager	>= 1.30, <= 1.39	cpe:2.3:a:intel:connection_manager::::::::
debian	debian_linux	9.0	cpe:2.3:o:debian:debian_linux:9.0:::::::*

References for CVE-2021-33833

URL	Tags
http://www.openwall.com/lists/oss-security/2021/06/09/1	Mailing List Third Party Advisory
http://www.openwall.com/lists/oss-security/2022/01/25/1	Exploit Mailing List Third Party Advisory
https://lists.debian.org/debian-lts-announce/2022/02/msg00009.html	Mailing List Third Party Advisory
https://lore.kernel.org/connman/	Vendor Advisory
https://security.gentoo.org/glsa/202107-29	Third Party Advisory

URL

CVE-2021-33833

Public exploit references (Exploit-DB) for CVE-2021-33833

Exploit prediction scoring system (EPSS) score for CVE-2021-33833

Common vulnerability scoring system (CVSS) metrics for CVE-2021-33833

Weakness enumeration for CVE-2021-33833

OS Trackers for CVE-2021-33833

Affected software / configurations for CVE-2021-33833

References for CVE-2021-33833