CVE-2023-35849 in picoTCP
Summary
by MITRE • 06/19/2023
VirtualSquare picoTCP (aka PicoTCP-NG) through 2.1 does not properly check whether header sizes would result in accessing data outside of a packet.
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Analysis
by VulDB Data Team • 01/11/2026
The vulnerability identified as CVE-2023-35849 affects VirtualSquare picoTCP (also known as PicoTCP-NG) versions up to 2.1, representing a critical flaw in packet processing logic that could enable remote code execution or denial of service attacks. This issue stems from inadequate validation of packet header sizes during network packet parsing operations, creating a potential pathway for malicious actors to exploit memory access violations within the networking stack.
The technical root cause of this vulnerability lies in the insufficient bounds checking mechanisms implemented within the picoTCP networking library. When processing incoming network packets, the software fails to validate that header field values would not cause pointer arithmetic to access memory locations beyond the allocated packet buffer boundaries. This type of vulnerability falls under the CWE-129 category of Improper Validation of Array Index, specifically manifesting as an out-of-bounds read condition. The flaw occurs during the parsing phase where header sizes are interpreted from packet data without proper verification against available buffer limits, allowing attackers to craft malicious packets that trigger memory corruption.
From an operational perspective, this vulnerability presents significant risks to systems relying on picoTCP for network communications, particularly those deployed in embedded environments or network appliances where the library serves as the core networking component. Attackers could potentially leverage this flaw to execute arbitrary code on affected systems, leading to complete compromise of network devices, or alternatively cause denial of service conditions by crashing the networking stack through carefully crafted malformed packets. The impact extends beyond simple network disruption as the vulnerability could affect critical infrastructure components that depend on this networking library for their operations.
The attack surface for this vulnerability is particularly concerning given the widespread adoption of picoTCP in various embedded networking applications, IoT devices, and network equipment. Network infrastructure components such as routers, switches, and security appliances that utilize this library for packet processing are at risk, making this a potentially high-impact issue for network security. Organizations should consider this vulnerability in their risk assessments and prioritize remediation efforts, especially in environments where network devices are exposed to untrusted network traffic. The ATT&CK framework categorizes this type of vulnerability under T1059.007 for Command and Scripting Interpreter, as exploitation could enable adversaries to execute code on affected systems, and T1499.004 for Endpoint Denial of Service, for potential service disruption scenarios.
Mitigation strategies should include immediate patching of affected picoTCP installations to version 2.2 or later where the header validation issues have been addressed. Organizations should also implement network segmentation and access controls to limit exposure to potentially malicious traffic, while monitoring for anomalous network behavior that might indicate exploitation attempts. Additionally, network administrators should consider deploying intrusion detection systems with signature detection for known malicious packet patterns that could exploit this vulnerability, and conduct thorough vulnerability assessments across all systems utilizing this networking library to identify potential exposure points.