CVE-2016-6866

slock allows attackers to bypass the screen lock via vectors involving an invalid password hash, which triggers a NULL pointer dereference and crash.

Published: 2017-02-15 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2016-6866 is rated Moderate Risk (59.8/100): CVSS High severity, with medium exploitation likelihood (EPSS 2.89%). Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2016-6866

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-17 2.84% 2.89% +0.06%
2 2026-06-15 1.70% 2.84% +1.14%
3 2026-05-27 — 1.70% —

Full EPSS history (9 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2016-6866

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.5 3.0 HIGH
CVSS:3.0/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]
5.0 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]

Weakness enumeration for CVE-2016-6866

OS Trackers for CVE-2016-6866

vendor priority summary link
alpine — CVE-2016-6866: 1 source package rows (slock); 7 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 7, open 0. https://security.alpinelinux.org/vuln/CVE-2016-6866
debian not yet assigned CVE-2016-6866 not yet assigned priority: Debian including 1 source packages (suckless-tools), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2016-6866
ubuntu low CVE-2016-6866 low priority: Ubuntu including 1 source packages (suckless-tools), 9 status rows across 9 suites (artful, bionic, cosmic, precise, trusty, upstream, xenial, yakkety, zesty): ignored 4, not-affected 3, released 2. https://ubuntu.com/security/CVE-2016-6866

Affected software / configurations for CVE-2016-6866

Vendor Product Version Raw CPE
suckless slock <= 1.3 cpe:2.3:a:suckless:slock:*:*:*:*:*:*:*:*
fedoraproject fedora 24 cpe:2.3:o:fedoraproject:fedora:24:*:*:*:*:*:*:*
fedoraproject fedora 25 cpe:2.3:o:fedoraproject:fedora:25:*:*:*:*:*:*:*

References for CVE-2016-6866

cvelogic Threat Intelligence