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NVD / CVE Program· CNA GitHub_M

CVE-2023-42800: Buffer overflow due to use of `strcpy` in `performRtspHandshake`

Noroxi assessment

Priority: Monitor (action score 36/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 1.8% (FIRST EPSS); higher than 79.4% of all records.
  • Anyone who can reach it over the internet can trigger it. No account or password is required. A user must open a link or visit a page. No special conditions are required; it is repeatable.
  • No fixed version is recorded, but the references include a patch (commit or PR) link.

Low priority for now. See the fix and affected versions sections below.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

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.

HighCVSS 8.8 · v3.1—No exploit No fix recorded
Published
Dec 14, 2023
Updated
Jun 17, 2026
EPSS
1.8% · 79th percentile

Report tools

JSON

Action score

36

Monitor

Low priority for now.

CVSS
35 / 40 · 8.8 / 10
CISA KEV
0 / 30 · Not listed
EPSS
1 / 30 · 1.8%

CISA SSVC decision

Exploitation
proof of concept
Automatable
no
Technical impact
total

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
8.8
CNA · GitHub_M
8.8
agree

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • No fixed version yet

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2023-42800

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

One daily email digest (06:00 UTC); connect a webhook for KEV listings and weaponized exploits instantly.

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
moonlight-streammoonlight-common-c
moonlight-streammoonlight
moonlight-streammoonlight embedded
moonlight-streammoonlight xbox
moonlight-streammoonlight tv
moonlight-streammoonlight switch
moonlight-streammoonlight vita

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • moonlight-stream moonlight8.4.0 and later · up to 8.5.0 inclusive
  • moonlight-stream moonlight10.10 and later · up to 11.0 inclusive
  • moonlight-stream moonlight0.10.22
  • moonlight-stream moonlight embedded2.6.0
  • moonlight-stream moonlight switch0.13 and later · up to 0.13.3 inclusive
  • moonlight-stream moonlight tv1.5.4 and later · up to 1.5.27 inclusive
  • moonlight-stream moonlight vita0.9.2 and later · up to 0.9.3 inclusive
  • moonlight-stream moonlight xbox1.12.0 and later · up to 1.14.40 inclusive
  • moonlight-stream moonlight-common-c2022-11-04 and later · before 2023-10-06

Versions reported by the vendor

Affected version ranges reported by the assigning authority (GitHub_M). Independent of NVD's CPE analysis and usually ahead of it.

  • moonlight-stream moonlight-common-c

    • >= 50c0a51b10ecc5b3415ea78c21d96d679e2288f9, < 24750d4b748fefa03d09fcfd6d45056faca354e0affected

Same product

moonlight-stream: all records

Other highest-scoring records for the same primary product.

  • CVE-2023-42799Buffer overflow due to use of `strcpy` in `parseUrlAddrFromRtspUrlString`
    36Monitor
  • CVE-2023-42801Stack buffer overflow due to `strcpy` into fixed size buffer in `extractVersionQuadFromString`
    30Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

No fix version is recorded for this entry. Check the references for vendor advisories.

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

No history yet (it accumulates with the daily EPSS job).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

  • CVE-2023-427990 days apartBuffer overflow due to use of `strcpy` in `parseUrlAddrFromRtspUrlString`
    36Monitor
  • CVE-2023-428010 days apartStack buffer overflow due to `strcpy` into fixed size buffer in `extractVersionQuadFromString`
    30Monitor

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • No account or password is required.
  • A user must open a link or visit a page.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
high · data can be read
Integrity
high · data or configuration can be modified
Availability
high · the service can be disrupted
Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
Required
Scope
Unchanged
Confidentiality impact
High
Integrity impact
High
Availability impact
High

Weakness class (CWE)

CWE-120 · Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

nvd-primary

Root cause

When data is copied, the source length is not compared with the size of the destination buffer. Excess data overwrites adjacent memory.

The bug in code

The whole CWE-120 class

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

Vulnerable

c
char buf[256];memcpy(buf, pkt->data, pkt->len);

Fixed

c
char buf[256];if (pkt->len > sizeof(buf)) {  return -EINVAL;}memcpy(buf, pkt->data, pkt->len);

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

ATT&CK techniques

—

Change log

No changes recorded on tracked fields yet. Score, KEV, exploit maturity and fix status changes appear here.

References

Show all references (2 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records