CVE-2016-6252 [High] | Integer Overflow in Shadow

CVE-2016-6252 is rated Moderate Risk (42.8/100): CVSS High severity, with low exploitation likelihood (EPSS 0.41%). Review affected assets and schedule remediation.

#	Date	Old EPSS score	New EPSS score	Delta (New - Old)
1	2026-06-15	0.10%	0.41%	+0.31%
2	2025-03-30	0.22%	0.10%	-0.13%
3	2025-03-29	—	0.22%	—

Date

Old EPSS score

New EPSS score

Delta (New - Old)

2026-06-15

0.10%

0.41%

+0.31%

2025-03-30

0.22%

0.10%

-0.13%

2025-03-29

—

0.22%

—

Base score	Version	Severity	Vector	Exploitability	Impact	Score source
7.8	3.0	HIGH	`CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H` Click to expand Attack vector (AV:L) They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by. 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: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.	1.8	5.9	[email protected]
4.6	2.0	MEDIUM	`AV:L/AC:L/Au:N/C:P/I:P/A:P` Click to expand Access vector (AV:L) Requires local access to the target system. 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.	3.9	6.4	[email protected]

Base score

Version

Severity

Vector

Exploitability

Impact

Score source

7.8

3.0

HIGH

CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H Click to expand

Attack vector (AV:L): They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
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: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.

1.8

5.9

[email protected]

4.6

2.0

MEDIUM

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

Access vector (AV:L): Requires local access to the target system.
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.

3.9

6.4

[email protected]

OS Trackers for CVE-2016-6252

vendor	priority	summary	link
`alpine`	—	CVE-2016-6252: 1 source package rows (shadow); 9 state rows across 7 repos (3.17-community, 3.18-community, 3.19-community, 3.20-community, 3.21-community, 3.22-community, edge-community); fixed 9, open 0.	https://security.alpinelinux.org/vuln/CVE-2016-6252
`debian`	not yet assigned	CVE-2016-6252 not yet assigned priority: Debian including 1 source packages (shadow), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5.	https://security-tracker.debian.org/tracker/CVE-2016-6252
`gentoo`	high	CVE-2016-6252: 1 GLSA(s) (201706-02), 1 atom(s) (sys-apps/shadow); latest impact high.	https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2016-6252
`redhat`	medium	—	https://access.redhat.com/security/cve/CVE-2016-6252
`suse`	high	CVE-2016-6252 severity important: SUSE including 16 source package names (0.9.1:shadow-4.2.1-27.9.1, 1.0.0:shadow-4.2.1-27.9.1, …), 50 product×package rows across 48 product lines (Container caasp/v4/default-http-backend, Container caasp/v4/dnsmasq-nanny, … (48 product lines)): Fixed 36, Known Not Affected 14.	https://www.suse.com/security/cve/CVE-2016-6252/
`ubuntu`	medium	CVE-2016-6252 medium priority: Ubuntu including 1 source packages (shadow), 7 status rows across 7 suites (precise, trusty, upstream, wily, xenial, yakkety, zesty): released 4, ignored 2, needs-triage 1.	https://ubuntu.com/security/CVE-2016-6252

Affected software / configurations for CVE-2016-6252

Vendor	Product	Version	Raw CPE
shadow_project	shadow	4.2.1	cpe:2.3:a:shadow_project:shadow:4.2.1:::::::*

References for CVE-2016-6252

URL	Tags
http://www.debian.org/security/2017/dsa-3793
http://www.openwall.com/lists/oss-security/2016/07/19/6	Mailing List Third Party Advisory
http://www.openwall.com/lists/oss-security/2016/07/19/7	Mailing List Third Party Advisory
http://www.openwall.com/lists/oss-security/2016/07/20/2	Mailing List Third Party Advisory
http://www.openwall.com/lists/oss-security/2016/07/25/7	Mailing List Patch Third Party Advisory
http://www.securityfocus.com/bid/92055	Third Party Advisory VDB Entry
https://bugzilla.suse.com/show_bug.cgi?id=979282	Issue Tracking Patch
https://github.com/shadow-maint/shadow/issues/27	Issue Tracking Patch Third Party Advisory
https://security.gentoo.org/glsa/201706-02

URL

CVE-2016-6252

Exploit prediction scoring system (EPSS) score for CVE-2016-6252

Common vulnerability scoring system (CVSS) metrics for CVE-2016-6252

Weakness enumeration for CVE-2016-6252

OS Trackers for CVE-2016-6252

Affected software / configurations for CVE-2016-6252

References for CVE-2016-6252