In Valve Steam 1528829181 BETA, it is possible to perform a homograph / homoglyph attack to create fake URLs in the client, which may trick users into visiting unintended web sites.

Valve Steam Client before 2019-09-12 allows placing or appending partially controlled filesystem content, as demonstrated by file modifications on Windows in the context of NT AUTHORITY\SYSTEM. This could lead to denial of service, elevation of privilege, or unspecified other impact.

An issue was discovered in Valve Steam Link build 643. When the SSH daemon is enabled for local development, the device is publicly available via IPv6 TCP port 22 over the internet (with stateless address autoconfiguration) by default, which makes it easier for remote attackers to obtain access by guessing 24 bits of the MAC address and attempting a root login. This can be exploited in conjunction with CVE-2017-17878.

An issue was discovered in Valve Steam Link build 643. Root passwords longer than 8 characters are truncated because of the default use of DES (aka the CONFIG_FEATURE_DEFAULT_PASSWD_ALGO="des" setting).

Valve Steam 3.42.16.13 uses weak permissions for the files in the Steam program directory, which allows local users to modify the files and possibly gain privileges as demonstrated by a Trojan horse Steam.exe file.

Valve Steam 2.10.91.91 uses weak permissions (Users: read and write) for the Install folder, which allows local users to gain privileges via a Trojan horse steam.exe file.

The client detection protocol in Valve Steam allows remote attackers to cause a denial of service (process crash) via a crafted response to a broadcast packet.

Valve Bug Reporter in the valve-bugreporter package 2.10+bsos1 in Valve SteamOS Beta stores cleartext credentials in a .valve-bugreporter.cfg file upon a Remember Credentials action, which allows local users to obtain sensitive information by reading this file.

Valve Software Half-Life Counter-Strike 1.6 allows remote attackers to cause a denial of service (crash) via multiple crafted login packets.