CVE-2020-5138
CVE-2020-5138 is a high-severity vulnerability in Sonicwall Sonicos with a CVSS 3.x base score of 7.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-787.
Key facts
- Severity: High (CVSS 3.x base score 7.5)
- CVSS v2: 5.0
- EPSS exploit prediction: 2% (75th percentile)
- Actively exploited: Not listed in CISA KEV
- Weakness: CWE-787
- Affected product: Sonicwall Sonicos
- Published:
- Last modified:
Description
A Heap Overflow vulnerability in the SonicOS allows a remote unauthenticated attacker to cause Denial of Service (DoS) on the firewall SSLVPN service and leads to SonicOS crash. This vulnerability affected SonicOS Gen 5 version 5.9.1.7, 5.9.1.13, Gen 6 version 6.5.4.7, 6.5.1.12, 6.0.5.3, SonicOSv 6.5.4.v and Gen 7 version SonicOS 7.0.0.0.
Frequently asked questions
- What is CVE-2020-5138?
- A Heap Overflow vulnerability in the SonicOS allows a remote unauthenticated attacker to cause Denial of Service (DoS) on the firewall SSLVPN service and leads to SonicOS crash. This vulnerability affected SonicOS Gen 5 version 5.9.1.7, 5.9.1.13, Gen 6 version 6.5.4.7, 6.5.1.12, 6.0.5.3, SonicOSv 6.5.4.v and Gen 7 version SonicOS 7.0.0.0.
- How severe is CVE-2020-5138?
- CVE-2020-5138 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
- Is CVE-2020-5138 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (75th percentile), an estimate of the probability of exploitation in the next 30 days.
- What products are affected by CVE-2020-5138?
- CVE-2020-5138 primarily affects Sonicwall Sonicos. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
- How do I fix CVE-2020-5138?
- Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
- When was CVE-2020-5138 published?
- CVE-2020-5138 was published on 2020-10-12 and last updated on 2026-06-17.
References
Affected products (3)
- cpe:2.3:o:sonicwall:sonicos:*:*:*:*:*:*:*:*
- cpe:2.3:o:sonicwall:sonicos:7.0.0.0:*:*:*:*:*:*:*
- cpe:2.3:o:sonicwall:sonicosv:*:*:*:*:*:*:*:*
More vulnerabilities in Sonicwall Sonicos
- CVE-2025-40600 — Critical (CVSS 9.8): Use of Externally-Controlled Format String vulnerability in the SonicOS SSL VPN interface allows a remote…
- CVE-2024-53704 — Critical (CVSS 9.8): An Improper Authentication vulnerability in the SSLVPN authentication mechanism allows a remote attacker to bypass…
- CVE-2024-40766 — Critical (CVSS 9.8): An improper access control vulnerability has been identified in the SonicWall SonicOS management access, potentially…
- CVE-2024-22394 — Critical (CVSS 9.8): An improper authentication vulnerability has been identified in SonicWall SonicOS SSL-VPN feature, which in specific…
- CVE-2022-22274 — Critical (CVSS 9.8): A Stack-based buffer overflow vulnerability in the SonicOS via HTTP request allows a remote unauthenticated attacker to…
- CVE-2020-5135 — Critical (CVSS 9.8): A buffer overflow vulnerability in SonicOS allows a remote attacker to cause Denial of Service (DoS) and potentially…
All CVEs affecting Sonicwall Sonicos →
Other CWE-787 (Out-of-bounds Write) vulnerabilities
- CVE-2026-42369 — Critical (CVSS 10.0): GV-VMS V20 is a Video Monitoring Software used to gather the feeds of many surveillance cameras and manage other…
- CVE-2026-4746 — Critical (CVSS 10.0): Out-of-bounds Write vulnerability in timeplus-io proton (base/poco/Foundation/src modules). This vulnerability is…
- CVE-2025-43300 — Critical (CVSS 10.0): An out-of-bounds write issue was addressed with improved bounds checking. This issue is fixed in iOS 15.8.5 and iPadOS…
- CVE-2025-24201 — Critical (CVSS 10.0): An out-of-bounds write issue was addressed with improved checks to prevent unauthorized actions. This issue is fixed in…
- CVE-2024-42479 — Critical (CVSS 10.0): llama.cpp provides LLM inference in C/C++. The unsafe `data` pointer member in the `rpc_tensor` structure can cause…
- CVE-2024-39791 — Critical (CVSS 10.0): Stack-based buffer overflow vulnerabilities affecting Vonets industrial wifi bridge relays and wifi bridge…