⚠ Actively exploited in ransomware campaigns
This vulnerability is on the CISA Known Exploited Vulnerabilities list and has been used in known ransomware attacks. CISA required action: Apply updates per vendor instructions.. Due date: 2022-02-11.

CVE-2021-20038 — Stack-based Buffer Overflow in Sma100

CWE-121 — Stack-based Buffer OverflowCWE-787 — Out-of-bounds Write9 documents8 sources
Severity
9.8CRITICALNVD
EPSS
94.3%
top 0.06%
CISA KEV
KEVRansomware
Added 2022-01-28
Due 2022-02-11
Exploit
Exploited in wild
Active exploitation observed
Affected products
6
Sonicwall Sma100Sonicwall SMA 200 FirmwareSonicwall SMA 210 Firmware+3 more
Timeline
PublishedDec 8
KEV addedJan 28
KEV dueFeb 11
CISA Required Action: Apply updates per vendor instructions.

Description

A Stack-based buffer overflow vulnerability in SMA100 Apache httpd server's mod_cgi module environment variables allows a remote unauthenticated attacker to potentially execute code as a 'nobody' user in the appliance. This vulnerability affected SMA 200, 210, 400, 410 and 500v appliances firmware 10.2.0.8-37sv, 10.2.1.1-19sv, 10.2.1.2-24sv and earlier versions.

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HExploitability: 3.9 | Impact: 5.9

Affected Packages6 packages

▶NVDsonicwall/sma_500v_firmware10.2.0.8-37sv, 10.2.1.1-19sv, 10.2.1.2-24sv+2
▶CVEListV5sonicwall/sonicwall_sma10010.2.0.8-37sv and earlier, 10.2.1.1-19sv and earlier, 10.2.1.2-24sv and earlier+2
▶NVDsonicwall/sma_200_firmware10.2.0.8-37sv, 10.2.1.1-19sv, 10.2.1.2-24sv+2
▶NVDsonicwall/sma_210_firmware10.2.0.8-37sv, 10.2.1.1-19sv, 10.2.1.2-24sv+2
▶NVDsonicwall/sma_400_firmware10.2.0.8-37sv, 10.2.1.1-19sv, 10.2.1.2-24sv+2

🔴Vulnerability Details

3
GHSA
GHSA-jmhc-vxg9-h2g4: A Stack-based buffer overflow vulnerability in SMA100 Apache httpd server's mod_cgi module environment variables allows a remote unauthenticated attac↗2021-12-09
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CVEList
CVE-2021-20038: A Stack-based buffer overflow vulnerability in SMA100 Apache httpd server's mod_cgi module environment variables allows a remote unauthenticated attac↗2021-12-08
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VulnCheck
SonicWall SMA 100 Appliances Stack-Based Buffer Overflow Vulnerability↗2021
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💥Exploits & PoCs

1
Nuclei
SonicWall SMA100 Stack - Buffer Overflow/Remote Code Execution
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🔍Detection Rules

2
Suricata
ET EXPLOIT SonicWall SMA Stack-Based Buffer Overflow CVE-2021-20038 M1↗2022-01-26
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Suricata
ET EXPLOIT SonicWall SMA Stack-Based Buffer Overflow CVE-2021-20038 M2↗2022-01-26
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📋Vendor Advisories

1
CISA
SonicWall SMA 100 Appliances Stack-Based Buffer Overflow Vulnerability↗2022-01-28
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CVE-2021-20038 — Stack-based Buffer Overflow in Sma100 | cvebase