markparticle WebServer buffer.cpp HasWritten buffer overflow

published 2025-04-21 18 mo ago modified 2026-06-17 4 mo ago also EUVD-2025-12342

cvss: 7.3; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.7%; EPSS 0.7% chance of exploitation in 30 days, percentile 53%
public exploits: 0; none known

A vulnerability was found in markparticle WebServer up to 1.0. It has been declared as critical. Affected by this vulnerability is the function Buffer::HasWritten of the file code/buffer/buffer.cpp. The manipulation of the argument writePos_ leads to buffer overflow. The attack can be launched remotely. The exploit has been disclosed to the public and may be used.

CISA SSVC

Exploitation: Proof of concept is public
Automatable: yes
Technical impact: partial
Assessed: 18 mo ago (2025-04-22)

Exploit prediction

0.70% chance of exploitation in the next 30 days, higher than 53% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

magnificent-dill-351.notion.site https://magnificent-dill-351.notion.site/Arbitrary-Memory-Writing-in-WebServer-1-0-1d1c693918ed80889711ebd44f7f9a31 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by	version	score	vector
CNA	4.0	6.9	CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N
CNA	3.1	7.3	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L
CNA	3.0	7.3	CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L
CNA	2.0	7.5	AV:N/AC:L/Au:N/C:P/I:P/A:P
CNA	4.0	6.9	CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
NVD	3.1	9.8	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected products

markparticle WebServer

Classification

Weakness

CWE-120 Buffer Copy without Checking Size of Input
CWE-119 Improper Restriction of Operations within the Bounds of a Memory Buffer

References

magnificent-dill-351.notion.site /Arbitrary-Memory-Writing-in-WebServer-1-0-1d1c693918ed80889711ebd44f7f9a31
exploit, broken-link
vuldb.com /?id.305773
vdb-entry, technical-description, third-party-advisory
vuldb.com /?ctiid.305773
signature, permissions-required, vdb-entry
vuldb.com /?submit.556273
third-party-advisory, vdb-entry

Sources

CVE List CVE-2025-3845
NVD CVE-2025-3845

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