How severe is CVE-2017-8900?

CVE-2017-8900 has a CVSS 3.x base score of 4.6, rated medium severity. It is exploitable over physical access with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.

Is CVE-2017-8900 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (34th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2017-8900?

CVE-2017-8900 affects Lightdm Project Lightdm. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2017-8900?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2017-8900 published?

CVE-2017-8900 was published on 2017-05-12 and last updated on 2026-06-17.

CVE-2017-8900

CVE-2017-8900 is a medium-severity vulnerability in Lightdm Project Lightdm with a CVSS 3.x base score of 4.6. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low.

Key facts

Severity: Medium (CVSS 3.x base score 4.6)
CVSS v2: 2.1
EPSS exploit prediction: 0% (34th percentile)
Actively exploited: Not listed in CISA KEV
Affected product: Lightdm Project Lightdm
Published: 2017-05-12
Last modified: 2026-06-17

Description

LightDM through 1.22.0, when systemd is used in Ubuntu 16.10 and 17.x, allows physically proximate attackers to bypass intended AppArmor restrictions and visit the home directories of arbitrary users by establishing a guest session.

Frequently asked questions

What is CVE-2017-8900?: LightDM through 1.22.0, when systemd is used in Ubuntu 16.10 and 17.x, allows physically proximate attackers to bypass intended AppArmor restrictions and visit the home directories of arbitrary users by establishing a guest session.
How severe is CVE-2017-8900?: CVE-2017-8900 has a CVSS 3.x base score of 4.6, rated medium severity. It is exploitable over physical access with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.
Is CVE-2017-8900 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (34th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2017-8900?: CVE-2017-8900 affects Lightdm Project Lightdm. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2017-8900?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2017-8900 published?: CVE-2017-8900 was published on 2017-05-12 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:lightdm_project:lightdm:*:*:*:*:*:*:*:*

More vulnerabilities in Lightdm Project Lightdm

CVE-2011-3349 — High (CVSS 7.8): lightdm before 0.9.6 writes in .dmrc and Xauthority files using root permissions while the files are in user controlled…
CVE-2017-7358 — High (CVSS 7.3): In LightDM through 1.22.0, a directory traversal issue in debian/guest-account.sh allows local attackers to own…
CVE-2015-8316 — Medium (CVSS 5.9): 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…

All CVEs affecting Lightdm Project Lightdm →