CVE-2023-35855Public exploitNetwork attack vector

Client code execution via oversized lservercfgfile value

Published Jun 19, 2023 · Updated Dec 11, 2024

Buffer overflow in Counter-Strike through 8684 allows remote attackers controlling a game server to execute code on connecting clients. The server sends an oversized lservercfgfile console-variable value, which the client copies without adequate bounds before a forced map change triggers execution. A client must connect to the malicious server and receive the crafted command; successful exploitation runs arbitrary code with the game process's privileges.

CVSS severity9.8
Critical
EPSS probability1.07%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Buffer overflow in Counter-Strike through 8684 allows remote attackers controlling a game server to execute code on connecting clients. The server sends an oversized lservercfgfile console-variable value, which the client copies without adequate bounds before a forced map change triggers execution. A client must connect to the malicious server and receive the crafted command; successful exploitation runs arbitrary code with the game process's privileges.

The record

CVE
CVE-2023-35855
Published
Jun 19, 2023
Updated
Dec 11, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-120, T1203
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 19, 2023CVE publishedPublication date reported by the CVE source.
  2. Dec 11, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

9.8NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-120Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')
T1203Exploitation for Client Execution

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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