CVE-2023-42801 Stack buffer overflow due to `strcpy` into fixed size buffer in `extractVersionQuadFromString`

High 7.6 Published 14 Dec 2023 Updated 2 Aug 2024

A malicious game streaming server can crash Moonlight clients or potentially execute code via a stack buffer overflow in the shared client library.

Exploited in the wild: Not known
Login needed: Not needed
Attackable: Over the internet
Victim action needed: A user has to click or open something
Fix: None listed

What is CVE-2023-42801?

CVE-2023-42801 is a high-severity memory corruption vulnerability in moonlight-stream moonlight-common-c, published on 14 Dec 2023. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

Official description

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.

Weakness: CWE-120

Which versions are affected by CVE-2023-42801?

It affects 8 products.

Products include Moonlight-Stream Moonlight, Moonlight-Stream Moonlight-Common-C, Moonlight-Stream Moonlight Embedded, Moonlight-Stream Moonlight Qt\/Pc, Moonlight-Stream Moonlight Switch, Moonlight-Stream Moonlight Tv and 2 more.

How do I fix CVE-2023-42801?

No fix has been published for CVE-2023-42801 yet. Limit exposure of the affected software until one is available.

Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.

Is CVE-2023-42801 being exploited?

There is no known exploitation of CVE-2023-42801 in the wild and no public exploit code.

Sources

Also known as GHSA-f3h8-j898-5h5v.