VulnerabilityPublished 10 Oct 2025

CVE-2025-11618: AWS FreeRTOS-Plus-TCP · NULL Pointer Dereference

Affects AWS FreeRTOS-Plus-TCPSource CVE Database V5

Not known to be exploited · CVSS 5.3 Medium.

Data as of 26 Oct 2026, 14:05 UTC

CVSS 4.0 base score

5.3Medium

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.3% chance of exploitation in 30 days – higher than 26% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N

Attack Vector: Network
Attack Complexity: Low
Attack Requirements: None
Privileges Required: Low
User Interaction: None
Vulnerable system confidentiality: None
Vulnerable system integrity: None
Vulnerable system availability: Low
Subsequent system confidentiality: None
Subsequent system integrity: None
Subsequent system availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable system is bound to the network stack and the set of possible attackers extends beyond the other options listed below, up to and including the entire Internet. Such a vulnerability is often termed “remotely exploitable” and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: The attacker must take no measurable action to exploit the vulnerability. The attack requires no target-specific circumvention to exploit the vulnerability. An attacker can expect repeatable success against the vulnerable system.
Attack Requirements: None: The successful attack does not depend on the deployment and execution conditions of the vulnerable system. The attacker can expect to be able to reach the vulnerability and execute the exploit under all or most instances of the vulnerability.
Privileges Required: Low: The attacker requires privileges that provide basic capabilities that are typically limited to settings and resources owned by a single low-privileged user. Alternatively, an attacker with Low privileges has the ability to access only non-sensitive resources.
User Interaction: None: The vulnerable system can be exploited without interaction from any human user, other than the attacker.
Vulnerable system confidentiality: None: There is no loss of confidentiality within the Vulnerable System.
Vulnerable system integrity: None: There is no loss of integrity within the Vulnerable System.
Vulnerable system availability: Low: Performance is reduced or there are interruptions in resource availability. Even if repeated exploitation of the vulnerability is possible, the attacker does not have the ability to completely deny service to legitimate users. The resources in the Vulnerable System are either partially available all of the time, or fully available only some of the time, but overall there is no direct, serious consequence to the Vulnerable System.
Subsequent system confidentiality: None: There is no loss of confidentiality within the Subsequent System or all confidentiality impact is constrained to the Vulnerable System.
Subsequent system integrity: None: There is no loss of integrity within the Subsequent System or all integrity impact is constrained to the Vulnerable System.
Subsequent system availability: None: There is no impact to availability within the Subsequent System or all availability impact is constrained to the Vulnerable System.

Definitions: FIRST CVSS v4.0 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 10 Oct 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Affected software

Product	Affected	Fixed in
AWS FreeRTOS-Plus-TCP	Affected =4.0.0	Fixed in–

AI-suggested

Upgrade all AWS FreeRTOS-Plus-TCP deployments to the latest version that includes the patch for CVE-2025-11618.
Audit and patch any forks or derivative codebases that incorporate FreeRTOS-Plus-TCP to ensure the validation fix is applied.
Implement network-level filtering to block malformed or suspicious IPv6 UDP packets, especially those with invalid IP version fields, to reduce exposure.
Monitor device logs and network traffic for anomalies indicative of malformed packet attempts or crashes.
Employ robust device management and update mechanisms to rapidly deploy patches across distributed IoT and embedded device fleets.
Where feasible, segment IoT networks to limit exposure of vulnerable devices to untrusted networks.
Conduct regular security assessments of embedded network stacks and protocol implementations to identify similar validation weaknesses early. These steps go beyond generic advice by focusing on patch management, network filtering, and proactive monitoring tailored to embedded IPv6 environments.

Description

A missing validation check in FreeRTOS-Plus-TCP's UDP/IPv6 packet processing code can lead to an invalid pointer dereference when receiving a UDP/IPv6 packet with an incorrect IP version field in the packet header. This issue only affects applications using IPv6. We recommend upgrading to the latest version and ensure any forked or derivative code is patched to incorporate the new fixes.

Impact

For European organizations, the primary impact of CVE-2025-11618 is potential denial of service on embedded and IoT devices running AWS FreeRTOS-Plus-TCP with IPv6 enabled. This can lead to temporary unavailability of critical systems, especially in industrial control, manufacturing automation, smart city infrastructure, and healthcare devices that rely on embedded networking stacks. While the vulnerability does not directly compromise confidentiality or integrity, disruption of availability can have cascading effects on operational continuity and safety. Organizations with large deployments of IoT devices using FreeRTOS-Plus-TCP may face increased risk of network instability or device failures if targeted. The lack of known exploits reduces immediate risk, but the ease of remote exploitation and absence of required user interaction mean attackers could weaponize this vulnerability in the future. European entities involved in critical infrastructure or with stringent uptime requirements should prioritize remediation to avoid service interruptions and potential regulatory scrutiny related to operational resilience.

CWE-476NULL Pointer Dereference (opens in a new tab)
Base weaknessLikelihood of exploit: MediumCWE Top 25 (2025): #13OWASP Top 10 A10:2025: Mishandling of Exceptional Conditions (opens in a new tab)
The product dereferences a pointer that it expects to be valid but is NULL.
Implementation
For any pointers that could have been modified or provided from a function that can return NULL, check the pointer for NULL before use. When working with a multithreaded or otherwise asynchronous environment, ensure that proper locking APIs are used to lock before the check, and unlock when it has finished.
Requirements
Select a programming language that is not susceptible to these issues.
Implementation
Check the results of all functions that return a value and verify that the value is non-null before acting upon it.
OWASP Cheat Sheets
Logging (opens in a new tab)
Error Handling (opens in a new tab)
OWASP ASVS 4.0.3
V11.1.7 (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

Community reviews

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 10 Oct 2025, 17:25 UTC

WeaknessesCWE-476

Technical details

References

Community reviews

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