CVE-2025-40597: SonicWall SMA100 Series Web Interface Heap Overflow
Welcome back to the blog! Today, we're diving into a newly disclosed vulnerability affecting the SonicWall SMA100 series. This is a critical vulnerability, so let's get right to it.
🔍 TL;DR Summary
A heap-based buffer overflow vulnerability exists in the web interface of the SonicWall SMA100 series. This allows unauthenticated remote attackers to potentially cause a Denial of Service (DoS) or even achieve remote code execution. Patch immediately if you're using an affected version!
🚨 Vulnerability Details
- CVE ID: CVE-2025-40597
- Description: A heap-based buffer overflow vulnerability in the SMA100 series web interface allows remote, unauthenticated attacker to cause Denial of Service (DoS) or potentially results in code execution.
- CVSS Score: 7.5 (HIGH)
- CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- CVSS Explanation: The CVSS vector indicates that this vulnerability is remotely exploitable over the network (AV:N) with low attack complexity (AC:L) and doesn't require any privileges (PR:N) or user interaction (UI:N). The scope is unchanged (S:U), with no impact on confidentiality (C:N) or integrity (I:N), but there is a high impact on availability (A:H), meaning successful exploitation could lead to a Denial of Service.
- Exploit Requirements: The attacker needs network access to the SMA100 web interface. No authentication is required.
- Affected Vendor: SonicWall
- Affected Product: SMA100 Series
- Affected Version: Specific versions are detailed in the SonicWall advisory (linked below).
- CWE: CWE-122 - Heap-based Buffer Overflow. This means that the vulnerability arises from writing data beyond the allocated memory on the heap, potentially overwriting adjacent data structures and leading to unpredictable behavior, crashes, or code execution.
📅 Timeline of Events
- 2025-07-23: CVE ID assigned and vulnerability details published by SonicWall.
🧠 Exploitability & Real-World Risk
Given that this vulnerability doesn't require authentication and can be exploited remotely, it poses a significant risk. In the real world, an attacker could exploit this to disrupt services provided by the SMA100 appliance, potentially impacting remote access and VPN connectivity for organizations. The potential for remote code execution elevates the risk even further, as attackers could gain control of the device and use it as a foothold for further attacks within the network.
🛠️ Recommendations
The most important recommendation is to immediately apply the patch provided by SonicWall. Here are some additional best practices:
- Regularly update your SonicWall appliances with the latest security patches.
- Monitor your network for suspicious activity.
- Implement network segmentation to limit the impact of a potential breach.
🧪 Technical Insight
A heap-based buffer overflow typically occurs when a program writes more data to a memory buffer located on the heap than it can hold. This can overwrite adjacent data, leading to crashes or, more dangerously, allow an attacker to inject and execute malicious code. Without more specifics from the advisory, we can assume that some unsanitized input to the web interface is being used to allocate and write to a heap buffer.
🙌 Credit to Researcher(s)
Credit to SonicWall PSIRT for discovering and disclosing this vulnerability.
🔗 References
🧵 Tags
#SonicWall #SMA100 #HeapOverflow #CVE-2025-40597 #Security #Vulnerability #DoS #RCE #WebInterface
Summary: A heap-based buffer overflow vulnerability exists in the SonicWall SMA100 series web interface. An unauthenticated remote attacker can exploit this to cause a Denial of Service or potentially execute code. Apply the patch immediately.
CVE ID: CVE-2025-40597
Risk Analysis: Successful exploitation could lead to denial of service affecting VPN connectivity, or potentially remote code execution allowing the attacker to compromise the device and network.
Recommendation: Apply the security patch provided by SonicWall immediately. Monitor network traffic for suspicious activity.
Timeline
- 2025-07-23: CVE-2025-40597 published by SonicWall PSIRT