zephyrproject-rtos Zephyr up to 4.2 buffer overflow

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
6.9$0-$5k0.00

Summaryinfo

A vulnerability, which was classified as critical, has been found in zephyrproject-rtos Zephyr up to 4.2. This issue affects some unknown processing. Performing a manipulation results in buffer overflow. This vulnerability is cataloged as CVE-2025-9557. The attack must originate from the local network. There is no exploit available.

Detailsinfo

A vulnerability, which was classified as critical, was found in zephyrproject-rtos Zephyr up to 4.2. This affects an unknown functionality. The manipulation with an unknown input leads to a buffer overflow vulnerability. CWE is classifying the issue as CWE-120. The product copies an input buffer to an output buffer without verifying that the size of the input buffer is less than the size of the output buffer, leading to a buffer overflow. This is going to have an impact on confidentiality, integrity, and availability. The summary by CVE is:

‭An out-of-bound write can lead to an arbitrary code execution. Even on devices with some form of memory protection, this can still lead to‬ ‭a crash and a resultant denial of service.‬

It is possible to read the advisory at github.com. This vulnerability is uniquely identified as CVE-2025-9557 since 08/27/2025. The exploitability is told to be easy. The attack can only be done within the local network. No form of authentication is needed for exploitation. The technical details are unknown and an exploit is not publicly available. The pricing for an exploit might be around USD $0-$5k at the moment (estimation calculated on 11/27/2025).

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2025-199711). Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Productinfo

Type

Vendor

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 6.9
VulDB Meta Temp Score: 6.9

VulDB Base Score: 6.3
VulDB Temp Score: 6.3
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 7.6
CNA Vector (zephyr): 🔒

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Buffer overflow
CWE: CWE-120 / CWE-119
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Partially

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: no mitigation known
Status: 🔍

0-Day Time: 🔒

Timelineinfo

08/27/2025 CVE reserved
11/26/2025 +91 days Advisory disclosed
11/26/2025 +0 days VulDB entry created
11/27/2025 +1 days VulDB entry last update

Sourcesinfo

Product: github.com

Advisory: github.com
Status: Confirmed

CVE: CVE-2025-9557 (🔒)
GCVE (CVE): GCVE-0-2025-9557
GCVE (VulDB): GCVE-100-333579
EUVD: 🔒

Entryinfo

Created: 11/26/2025 06:54
Updated: 11/27/2025 13:41
Changes: 11/26/2025 06:54 (62), 11/26/2025 16:04 (1), 11/27/2025 13:41 (1)
Complete: 🔍
Cache ID: 216::103

Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

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