CVE intelligence and bounded remediation

CVE-2023-42801 — Moonlight-common-c contains the core GameStream client code shared between Moonlight clients

High CVSS 7.6

Moonlight-common-c contains the core GameStream client code shared between Moonlight clients. Moonlight-common-c is vulnerable to buffer overflow starting in commit f57bd745b4cbed577ea654fad4701bea4d38b44c. A malicious game streaming server could exploit a buffer overflow vulnerability to crash a moonlight client. Achieving RCE is possible but unlikely, due to stack canaries in use by modern compiler toolchains. The published binaries for official clients Qt, Android, iOS/tvOS, and Embedded are built with stack canaries, but some unofficial clients may not use stack canaries. This vulnerability takes place after the pairing process, so it requires the client to be tricked into pairing to a malicious host. It is not possible to perform using a man-in-the-middle due to public key pinning that takes place during the pairing process. The bug was addressed in commit b2497a3918a6d79808d9fd0c04734786e70d5954.

Severity
High
CVSS
7.6 (3.1)
Published
2023-12-14
CISA KEV
Not currently listed
Ecosystem
software/application
Weaknesses
CWE-120

Affected products

  • moonlight-stream / moonlight-common-c
  • moonlight-stream / moonlight
  • moonlight-stream / moonlight_embedded
  • moonlight-stream / moonlight_xbox
  • moonlight-stream / moonlight_tv
  • moonlight-stream / moonlight_switch

Showing 6 representative product identities from 11 source matches. Confirm exact affected versions with the linked vendor and NVD evidence.

Matched remediation archetype

Buffer bounds, memory safety, and memory corruption

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Check exposure

  • Identify affected native-code versions, build flags, architectures, parsers, codecs, drivers, and input paths in all shipped artifacts.
  • Determine whether untrusted data reaches the affected routine and the process privilege, sandbox, and network exposure.
  • Confirm statically linked, vendored, firmware, and platform-provided copies, not only package-manager records.

Remediate safely

  • Apply the maintained upstream correction or replace the affected component, then rebuild every dependent artifact from clean inputs.
  • Adopt bounds-checked interfaces, validated sizes and integer conversions, clear ownership, and memory-safe components where practical.
  • Enable supported compiler and runtime hardening and add sanitized tests and fuzz regression seeds derived from non-weaponized fixtures.

Authoritative sources

Complete CVE record and remediation plan

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