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

Valve Source SDK Stack-Based Buffer Overflow RCE

Valve's Source SDK (source-sdk-2013)'s ragdoll model parsing logic contains a stack-based buffer overflow vulnerability.The tokenizer function `nexttoken` copies characters from an input string into a fixed-size stack buffer without performing bounds checks. When `ParseKeyValue` processes a collisionpair rule longer than the destination buffer (256 bytes), an overflow of the stack buffer `szToken` can occur and overwrite the function return address. A remote attacker can trigger the vulnerable code by supplying a specially crafted ragdoll model which causes the oversized collisionpair rule to be parsed, resulting in remote code execution on affected clients or servers. Valve has addressed this issue in many of their Source games, but independently-developed games must manually apply patch.

Valve Steam before 2021-04-17, when a Source engine game is installed, allows remote authenticated users to execute arbitrary code because of a buffer overflow that occurs for a Steam invite after one click.

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.

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.

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).

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 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.

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.

A buffer overflow in the component hl.exe of Valve Half-Life up to 5433873 allows attackers to execute arbitrary code and escalate privileges by supplying crafted parameters.

A buffer overflow in Counter-Strike through 8684 allows a game server to execute arbitrary code on a remote client's machine by modifying the lservercfgfile console variable.

A directory traversal vulnerability in Valve Counter-Strike 8684 allows a client (with remote control access to a game server) to read arbitrary files from the underlying server via the motdfile console variable.

meshsystem.dll in Valve Dota 2 through 2020-02-17 allows remote attackers to achieve code execution or denial of service by creating a gaming server with a crafted map, and inviting a victim to this server. A GetValue call is mishandled.

rendersystemdx9.dll in Valve Dota 2 before 7.23f allows remote attackers to achieve code execution or denial of service by creating a gaming server and inviting a victim to this server, because a crafted map is affected by memory corruption.

meshsystem.dll in Valve Dota 2 before 7.23e allows remote attackers to achieve code execution or denial of service by creating a gaming server and inviting a victim to this server, because a crafted map is affected by memory corruption.

meshsystem.dll in Valve Dota 2 before 7.23f allows remote attackers to achieve code execution or denial of service by creating a gaming server and inviting a victim to this server, because a crafted map is mishandled during a vulnerable function call.

schemasystem.dll in Valve Dota 2 before 7.23f allows remote attackers to achieve code execution or denial of service by creating a gaming server and inviting a victim to this server, because a crafted map is mishandled during a GetValue call.

Valve's Game Networking Sockets prior to version v1.2.0 improperly handles inlined statistics messages in function CConnectionTransportUDPBase::Received_Data(), leading to an exception thrown from libprotobuf and resulting in a crash.

Valve's Game Networking Sockets prior to version v1.2.0 improperly handles long encrypted messages in function AES_GCM_DecryptContext::Decrypt() when compiled using libsodium, leading to a Stack-Based Buffer Overflow and resulting in a memory corruption and possibly even a remote code execution.

Valve's Game Networking Sockets prior to version v1.2.0 improperly handles long unreliable segments in function SNP_ReceiveUnreliableSegment() when configured to support plain-text messages, leading to a Heap-Based Buffer Overflow and resulting in a memory corruption and possibly even a remote code execution.