Buffer overflow due to use of `strcpy` in `performRtspHandshake`

published 2023-12-14 2 y ago modified 2026-06-17 4 mo ago also EUVD-2023-47227

cvss: 8.8; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 1.9%; EPSS 1.9% chance of exploitation in 30 days, percentile 79%
public exploits: 0; none known

Moonlight-common-c contains the core GameStream client code shared between Moonlight clients. Moonlight-common-c is vulnerable to buffer overflow starting in commit 50c0a51b10ecc5b3415ea78c21d96d679e2288f9 due to unmitigated usage of unsafe C functions and improper bounds checking. A malicious game streaming server could exploit a buffer overflow vulnerability to crash a moonlight client, or achieve remote code execution (RCE) on the client (with insufficient exploit mitigations or if mitigations can be bypassed). The bug was addressed in commit 24750d4b748fefa03d09fcfd6d45056faca354e0.

Patch / fix

fixed in 1 links 2

moonlight-stream moonlight-common-c 2023-10-06

CISA SSVC

Exploitation: Proof of concept is public
Automatable: no
Technical impact: total
Assessed: 23 mo ago (2024-11-27)

Exploit prediction

1.88% chance of exploitation in the next 30 days, higher than 79% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

github.com https://github.com/moonlight-stream/moonlight-common-c/security/advisories/GHSA-4927-23jw-rq62 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by	version	score	vector
CNA	3.1	8.8	CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
NVD	3.1	8.8	CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Affected products

moonlight-stream moonlight-common-c

Classification

Weakness

CWE-120 Buffer Copy without Checking Size of Input

References

Sources

CVE List CVE-2023-42800
NVD CVE-2023-42800

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary