CVE-2015-8316

Array index error in LightDM (aka Light Display Manager) 1.14.3, 1.16.x before 1.16.6 when the XDMCP server is enabled allows remote attackers to cause a denial of service (process crash) via an XDMCP request packet with no address.

Published: 2017-09-06 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2015-8316 is rated Moderate Risk (50.9/100): CVSS Medium severity, with medium exploitation likelihood (EPSS 1.75%). EPSS rose +1.16% over the last day, indicating growing attacker interest. 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-2015-8316

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 2026-06-15 0.59% 1.75% +1.16%
2 2025-03-30 0.82% 0.59% -0.23%
3 2025-03-29 — 0.82% —

Full EPSS history (7 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2015-8316

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
5.9 3.0 MEDIUM
CVSS:3.0/AV:N/AC:H/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:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
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.
 2.2 3.6 [email protected]
4.3 2.0 MEDIUM
AV:N/AC:M/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:M)
Exploitation needs some favorable conditions, but not exceptional ones.
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.
 8.6 2.9 [email protected]

Weakness enumeration for CVE-2015-8316

OS Trackers for CVE-2015-8316

vendor priority summary link
debian not yet assigned CVE-2015-8316 not yet assigned priority: Debian including 1 source packages (lightdm), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2015-8316
ubuntu low CVE-2015-8316 low priority: Ubuntu including 1 source packages (lightdm), 6 status rows across 6 suites (precise, trusty, upstream, vivid, wily, xenial): not-affected 3, DNE 1, ignored 1, released 1. https://ubuntu.com/security/CVE-2015-8316

Affected software / configurations for CVE-2015-8316

Vendor Product Version Raw CPE
lightdm_project lightdm 1.14.3 cpe:2.3:a:lightdm_project:lightdm:1.14.3:*:*:*:*:*:*:*
lightdm_project lightdm 1.16 cpe:2.3:a:lightdm_project:lightdm:1.16:*:*:*:*:*:*:*
lightdm_project lightdm 1.16.1 cpe:2.3:a:lightdm_project:lightdm:1.16.1:*:*:*:*:*:*:*
lightdm_project lightdm 1.16.2 cpe:2.3:a:lightdm_project:lightdm:1.16.2:*:*:*:*:*:*:*
lightdm_project lightdm 1.16.3 cpe:2.3:a:lightdm_project:lightdm:1.16.3:*:*:*:*:*:*:*
lightdm_project lightdm 1.16.4 cpe:2.3:a:lightdm_project:lightdm:1.16.4:*:*:*:*:*:*:*

References for CVE-2015-8316

URL Tags
http://www.openwall.com/lists/oss-security/2015/11/22/1 Mailing List VDB Entry
https://bugs.launchpad.net/lightdm/+bug/1516831 Issue Tracking Third Party Advisory VDB Entry
https://bugzilla.redhat.com/show_bug.cgi?id=1284574 Issue Tracking Third Party Advisory VDB Entry
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