CVE-2019-15316

low-risk
Published 2019-08-21

Valve Steam Client for Windows through 2019-08-20 has weak folder permissions, leading to privilege escalation (to NT AUTHORITY\SYSTEM) via crafted use of CreateMountPoint.exe and SetOpLock.exe to leverage a TOCTOU race condition.

Do I need to act?

-
0.05% chance of exploitation
EPSS score — low exploit probability
-
Not on CISA KEV list
No confirmed active exploitation reported to CISA
?
Patch status unknown
Check vendor advisories for fix availability and mitigation guidance
7
CVSS 7.0/10 High
LOCAL / HIGH complexity

Affected Products (1)

Steam Client

Affected Vendors

Valvesoftware

References (8)

Third Party Advisory https://amonitoring.ru/article/onemore_steam_eop_0day/
Third Party Advisory https://habr.com/ru/company/pm/blog/464367/
Exploit https://www.youtube.com/watch?v=I93aH86BUaE
Exploit https://www.youtube.com/watch?v=ZCHrjP0cMew
Third Party Advisory https://amonitoring.ru/article/onemore_steam_eop_0day/
Third Party Advisory https://habr.com/ru/company/pm/blog/464367/
Exploit https://www.youtube.com/watch?v=I93aH86BUaE
Exploit https://www.youtube.com/watch?v=ZCHrjP0cMew
23
/ 100
low-risk
Severity 18/34 · Moderate
Exploitability 0/34 · Minimal
Exposure 5/34 · Minimal