CVE-2017-7358: In LightDM through 1.22.0, a directory traversal issue in debian/guest-account.sh allows local attackers to ow

Q: How do I fix CVE-2017-7358?

lightdm: upgrade to newer than 1.22.0; ubuntu linux: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Q: Is CVE-2017-7358 being exploited?

CVE-2017-7358 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2017-7358 affect?

CVE-2017-7358 affects lightdm, ubuntu linux. Severity is high (CVSS 7.3). In LightDM through 1.22.0, a directory traversal issue in debian/guest-account.sh allows local attackers to own arbitrary directory path locations and escalate privileges to root when the guest user logs out.

Q: How urgent is CVE-2017-7358?

Priority 57/100. High severity; Public exploit reference; On your watchlist

This month

HIGH 7.3WATCHLISTUPGRADEMITIGATE

CVE-2017-7358 is a high-severity flaw (CVSS 7.3) affecting lightdm, ubuntu linux. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

In LightDM through 1.22.0, a directory traversal issue in debian/guest-account.sh allows local attackers to own arbitrary directory path locations and escalate privileges to root when the guest user logs out.

Why this priority

High severity
Public exploit reference
On your watchlist

A fixed release or distro patch exists.

Risk facts

CVSS score	7.3 (High)
Attack vector	Local
Attack complexity	Low
Privileges needed	Low
User interaction	Required
EPSS exploit chance	2.7% (top 14%)
CISA exploited list	No
Weakness	CWE-22
Published	2017-04-05
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: canonical · lightdm project

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2017-04-05 06:59 UTCPublished CVE record published
2026-06-17 01:24 UTCUpdated Record last modified

lightdm project lightdm UPGRADE

Affected: <= 1.22.0

Fixed in: newer than 1.22.0

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy lightdm || rpm -q lightdm || lightdm --version

2. UPGRADE to newer than 1.22.0 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade lightdm

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade lightdm

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

canonical ubuntu linux MITIGATE

Affected: 16.04 · 16.10

Fixed in: no fixed release known

Safe to downgrade to: a release before 16.04

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

Public exploits and detection

Public code exists for this CVE. Treat unpatched systems as at risk, and only run PoCs in a lab.

Exploit-DB: LightDM (Ubuntu 16.04/16.10) - 'Guest Account' Local Privilege Escalation

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2017-7358?

lightdm: upgrade to newer than 1.22.0; ubuntu linux: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2017-7358 being exploited?

CVE-2017-7358 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2017-7358 affect?

CVE-2017-7358 affects lightdm, ubuntu linux. Severity is high (CVSS 7.3). In LightDM through 1.22.0, a directory traversal issue in debian/guest-account.sh allows local attackers to own arbitrary directory path locations and escalate privileges to root when the guest user logs out.

How urgent is CVE-2017-7358?

Priority 57/100. High severity; Public exploit reference; On your watchlist

Software pages

Ubuntu vulnerabilities · Debian vulnerabilities

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CVE-2015-8316 MEDIUM 5.9 DOWNGRADE Array index error in LightDM (aka Light Display Manager) 1.14.3, 1.16.x before 1.16.6 when the XDMCP server is
CVE-2011-3349 HIGH 7.8 UPGRADE lightdm before 0.9.6 writes in .dmrc and Xauthority files using root permissions while the files are in user c

References

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