CVE-2023-35848Network attack vector

Denial of service via MSS size underflow

Published Jun 19, 2023 · Updated Dec 11, 2024

Incorrect calculation in VirtualSquare picoTCP through 2.1 allows remote attackers to interrupt service through TCP connection handling. An undersized socket MTU causes unsigned wraparound before the MSS member is assigned; upstream added a lower bound in pico_tcp_open, pico_tcp_initconn, and tcp_syn. No authentication or user interaction is required, but public sources do not specify whether the interruption is a hang, crash, or another failure mode.

CVSS severity7.5
High
EPSS probability0.70%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Incorrect calculation in VirtualSquare picoTCP through 2.1 allows remote attackers to interrupt service through TCP connection handling. An undersized socket MTU causes unsigned wraparound before the MSS member is assigned; upstream added a lower bound in pico_tcp_open, pico_tcp_initconn, and tcp_syn. No authentication or user interaction is required, but public sources do not specify whether the interruption is a hang, crash, or another failure mode.

The record

CVE
CVE-2023-35848
Published
Jun 19, 2023
Updated
Dec 11, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-682, T1499.004
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

7.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-682Incorrect Calculation
T1499.004Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

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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