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

Exp

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.

Published: 2023-12-14 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2023-42801 is rated High Exploit Risk (65.6/100): CVSS High severity, with medium exploitation likelihood (EPSS 0.36%). 2 public exploit reference(s) are indexed (Exploit-DB). Public exploits are available—assess exposure, apply mitigations, and prioritize patching.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Public exploit references (Exploit-DB) for CVE-2023-42801

EDB-ID Source Kind Published Link
— nvd_ref exploit_tag Exploit-DB ↗
— nvd_ref exploit_tag Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2023-42801

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2025-11-21 0.33% 0.36% +0.03%
2 2025-11-18 0.36% 0.33% -0.03%
3 2025-05-04 — 0.36% —

Full EPSS history (5 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2023-42801

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.6 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 2.8 4.7 [email protected]
7.6 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 2.8 4.7 [email protected]

Weakness enumeration for CVE-2023-42801

Affected software / configurations for CVE-2023-42801

Vendor Product Version Raw CPE
moonlight-stream moonlight-common-c >= 2016-10-05, < 2023-10-06 cpe:2.3:a:moonlight-stream:moonlight-common-c:*:*:*:*:*:*:*:*
moonlight-stream moonlight < 9.0.0 cpe:2.3:a:moonlight-stream:moonlight:*:*:*:*:*:iphone_os:*:*
moonlight-stream moonlight < 9.0.0 cpe:2.3:a:moonlight-stream:moonlight:*:*:*:*:*:tvos:*:*
moonlight-stream moonlight < 12.0 cpe:2.3:a:moonlight-stream:moonlight:*:*:*:*:*:android:*:*
moonlight-stream moonlight < 0.10.23 cpe:2.3:a:moonlight-stream:moonlight:*:*:*:*:*:chrome:*:*
moonlight-stream moonlight_embedded < 2.6.1 cpe:2.3:a:moonlight-stream:moonlight_embedded:*:*:*:*:*:*:*:*
moonlight-stream moonlight_xbox <= 1.14.5 cpe:2.3:a:moonlight-stream:moonlight_xbox:*:*:*:*:*:*:*:*
moonlight-stream moonlight_tv < 1.6.0 cpe:2.3:a:moonlight-stream:moonlight_tv:*:*:*:*:*:*:*:*
moonlight-stream moonlight_switch < 0.13.4 cpe:2.3:a:moonlight-stream:moonlight_switch:*:*:*:*:*:*:*:*
moonlight-stream moonlight_vita — cpe:2.3:a:moonlight-stream:moonlight_vita:*:*:*:*:*:*:*:*
moonlight-stream moonlight_qt\/pc <= 5.0.0 cpe:2.3:a:moonlight-stream:moonlight_qt\/pc:*:*:*:*:*:*:*:*

References for CVE-2023-42801

cvelogic Threat Intelligence