EUVD-2026-43243Vulnerability Assessment
| Weakness |
CWE
ASVS 5.0
V15 - Secure Coding and Architecture Bounds checking, write limits
MITRE ATT&CK
2 techniques across 2 tactics: Execution, Privilege Escalation The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up. |
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Alert meAnalysisAIv2 – Jul 17, 2026
Stack out-of-bounds write in the Zephyr RTOS network IP-parsing utility (parse_ipv4() in subsys/net/ip/utils.c) lets a crafted "a.b.c.d:port" address string with an overlong post-colon suffix overflow a 17-byte stack buffer with fully attacker-controlled length and contents, affecting Zephyr 1.9.0 through 4.4.0. Any application that resolves a network-influenced address string via the standard socket API (zsock_getaddrinfo/literal resolution), DNS server-string configuration, or the eswifi Wi-Fi DNS-response path is exposed, yielding at minimum denial of service and potentially control-flow hijack. No public exploit identified at time of analysis and it is not listed in CISA KEV; SSVC records proof-of-concept maturity and EPSS is low at 0.35%.
Earlier versions of this analysis (1)
Out-of-bounds stack write in the Zephyr RTOS IPv4 address parser (parse_ipv4() in subsys/net/ip/utils.c) lets an attacker corrupt memory when an application resolves an attacker-influenced "a.b.c.d:port" string, causing at minimum denial of service and potentially control-flow hijack on the affected embedded device. The defect exists in every release from v1.9.0 through v4.4.0 and is reachable through the standard socket resolver (zsock_getaddrinfo), DNS server-string configuration, and the eswifi Wi-Fi DNS-response path. There is no public exploit identified at time of analysis and it is not listed in CISA KEV, but a vendor fix (two upstream commits and advisory GHSA-532c-7g7f-jhmh) is available.
Affected VersionsENISA
Affected Packages
Source: OSV (Open Source Vulnerabilities)
Affects your stack
Affects 1 package in euvd
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- Exploit and PoC references, threat intelligence from 22 sources
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Severity by source
AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Primary rating from Vendor (zephyr).
CVSS VectorNVD
Lifecycle Timeline
2DescriptionNVD
parse_ipv4() in subsys/net/ip/utils.c (reached via net_ipaddr_parse() for strings of the form "a.b.c.d:port") copies the port substring into a fixed 17-byte stack buffer (char ipaddr[NET_IPV4_ADDR_LEN + 1]) using a length of str_len - end - 1, where str_len is the full, unbounded input length and end is only the (<=15-byte) offset of the ':' delimiter. Because the destination size is never consulted, a crafted address string with a long suffix after the colon (e.g. "1.2.3.4:" followed by hundreds of bytes) causes an out-of-bounds stack write whose length and contents are fully attacker-controlled (memcpy of the suffix plus a trailing NUL), enabling memory corruption and at minimum a denial of service, and potentially control-flow hijack. The parser is reached from the standard socket API (zsock_getaddrinfo / literal-address resolution), DNS server-string configuration, and the eswifi Wi-Fi co-processor DNS-response path, so an application that resolves a network-influenced address string is exposed. The bug was introduced when the parser was added (Zephyr v1.9.0) and shipped in all releases through v4.4.0. The fix removes the unbounded copy and validates the port length before copying into a small dedicated buffer. Note: the equivalent IPv6 "[addr]:port" path in parse_ipv6() retains the same unbounded copy at this commit and remains a separate, still-reachable instance of the defect.
Executive ViewAI
Zephyr RTOS versions 1.9.0 through 4.4.0 contain a critical stack overflow vulnerability in network address parsing that could enable denial of service or device compromise on embedded and IoT systems. Although no public exploit has been identified at time of analysis, the severity of this vulnerability requires prompt patching of any devices running vulnerable versions that handle network addresses through socket APIs, DNS configuration, or Wi-Fi DNS responses.
Within 24 hours, inventory all systems running Zephyr RTOS to identify which devices are running versions 1.9.0 through 4.4.0. Within 7 days, apply the vendor-released patch to all vulnerable systems after testing in development and staging environments to confirm network socket API and DNS resolution functionality remain unaffected. Prioritize production deployment within 30 days, with immediate priority for internet-facing devices or those receiving network configuration from untrusted sources.
Apply vendor patch.
Threat Intelligence Overview
NVD
CVE.org
EPSS
Vulnrichment
GitHub
VulDB
How this decision was reached
The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.
What every action level means
SSVC AssessmentENISA
Priority Score
Attack Technique
A buffer overflow occurs when a program writes more data to a memory buffer than it was allocated to hold, causing the excess data to spill into adjacent memory regions.
Memory corruption occurs when a program writes data beyond the boundaries of allocated memory regions or accesses memory in unintended ways, violating the integrity of the process's address space.
Denial of Service attacks render applications or systems unavailable by overwhelming resources or triggering failure conditions.
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