CVE-2025-53888: RIOT-OS Buffer Overflow Vulnerability
RIOT-OS, a popular operating system for IoT devices, is affected by a buffer overflow vulnerability. This flaw, identified as CVE-2025-53888, stems from an ineffective size check which, when assertions are disabled in production builds, can allow attackers to potentially cause a denial-of-service or even execute arbitrary code.
Vulnerability Details
- CVE ID: CVE-2025-53888
- Description: A buffer overflow vulnerability exists in RIOT-OS due to an ineffective size check in the `l2filter_add()` function. When assertions are disabled (as is common in production), a missing input check can allow an attacker to write past the `list[i].addr` buffer.
- CVSS Score: 6.6 (Medium)
- CVSS Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
- CVSS Explanation: This CVSS vector indicates a vulnerability that is exploitable over the network with low complexity and no user interaction. While confidentiality and integrity are not impacted, availability is significantly affected. An attacker could potentially crash the device.
- Exploit Requirements: An attacker needs to provide an `addr_len` value larger than `CONFIG_L2FILTER_ADDR_MAXLEN` when assertions are disabled.
- Affected Vendor: RIOT-OS
- Affected Product: RIOT-OS
- Affected Version: Versions up to and including 2025.04
- CWE: CWE-120 - Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')
- CWE Explanation: CWE-120 describes a situation where software copies data from one buffer to another without ensuring that the destination buffer is large enough to hold the data. This can lead to a buffer overflow, where data is written beyond the allocated memory, potentially overwriting adjacent memory regions.
Timeline of Events
- 2025.04: Vulnerable version of RIOT-OS released.
- [Date of Discovery]: Vulnerability Discovered.
- f6f7de4ccc107c018630e4c15500825caf02e1c2: Patch committed to address the vulnerability.
- 2025-07-18: CVE-2025-53888 assigned and published.
Exploitability & Real-World Risk
The exploitability of this vulnerability depends on whether the RIOT-OS build is compiled with assertions enabled. In development environments, assertions are often enabled, which would catch the oversized input. However, in production environments, assertions are typically disabled for performance reasons, making the system vulnerable.
In a real-world scenario, an attacker could potentially exploit this vulnerability on an IoT device running RIOT-OS to cause a denial of service. In more sophisticated attacks, the attacker could potentially leverage the buffer overflow to execute arbitrary code, potentially compromising the entire device or network it's connected to.
Recommendations
- Apply the Patch: Apply the patch provided in commit f6f7de4ccc107c018630e4c15500825caf02e1c2.
- Upgrade RIOT-OS: Upgrade to a version of RIOT-OS that includes the fix for this vulnerability.
- Input Validation: Ensure that all inputs are properly validated and sanitized to prevent buffer overflows.
Technical Insight
The vulnerability exists in the `l2filter_add()` function within the `sys/net/link_layer/l2filter/l2filter.c` file. The `addr_len` parameter, representing the length of an address, is checked using an `assert()` statement. However, assertions are often compiled out in production builds, meaning the size check is effectively removed. This allows an attacker to provide an `addr_len` value that exceeds the buffer size (`CONFIG_L2FILTER_ADDR_MAXLEN`), leading to a buffer overflow when `memcpy()` is called.
Credit to Researcher(s)
This vulnerability was reported via GitHub Security Advisory.
References
Tags
#RIOT-OS #CVE-2025-53888 #BufferOverflow #IoTSecurity #DenialofService
Summary: A buffer overflow vulnerability exists in RIOT-OS due to an ineffective size check. When assertions are disabled in production, an attacker can write past a buffer, causing a denial of service or potentially executing arbitrary code. Applying the provided patch or upgrading to a fixed version is crucial for mitigating this risk.
CVE ID: CVE-2025-53888
Risk Analysis: Successful exploitation can lead to a denial of service or arbitrary code execution, potentially compromising the device and/or network.
Recommendation: Apply the patch provided in commit f6f7de4ccc107c018630e4c15500825caf02e1c2 or upgrade to a patched version of RIOT-OS. Ensure input validation is performed.
Timeline
- 2025-04: Vulnerable version of RIOT-OS released.
- f6f7de4ccc107c018630e4c15500825caf02e1c2: Patch committed to address the vulnerability.
- 2025-07-18: CVE-2025-53888 assigned and published.