Stack-Based Buffer Overflow in SMA100 Apache httpd Server by SonicWall
CVE-2021-20038

9.8CRITICAL

Key Information:

Vendor

Sonicwall
Status
Sonicwall Sma100
Vendor
CVE Published:
8 December 2021

Badges

💰 Ransomware👾 Exploit Exists🟡 Public PoC🟣 EPSS 94%🦅 CISA Reported

What is CVE-2021-20038?

A stack-based buffer overflow vulnerability in the Apache httpd server's mod_cgi module on SonicWall's SMA100 appliances could allow a remote, unauthenticated attacker to execute arbitrary code with the privileges of the 'nobody' user. This issue affects multiple SMA appliance models, specifically versions prior to firmware updates 10.2.0.8-37sv, 10.2.1.1-19sv, and 10.2.1.2-24sv. Users are advised to update their firmware to mitigate this risk and secure their systems against potential exploitation.

CISA has reported CVE-2021-20038

CISA provides regional cyber and physical services to support security and resilience across the United States. CISA monitor the most dangerious vulnerabilities and have identifed CVE-2021-20038 as being exploited and is known by the CISA as enabling ransomware campaigns.

The CISA's recommendation is: Apply updates per vendor instructions.

Affected Version(s)

SonicWall SMA100 10.2.0.8-37sv and earlier

SonicWall SMA100 10.2.1.1-19sv and earlier

SonicWall SMA100 10.2.1.2-24sv and earlier

Exploit Proof of Concept (PoC)

PoC code is written by security researchers to demonstrate the vulnerability can be exploited. PoC code is also a key component for weaponization which could lead to ransomware.

badblood
Created by jbaines-r7

CVE-2021-20038-SonicWall-RCE
Created by vesperp

References

https://psirt.global.sonicwall.com/vuln-detail/SNWLID-202...
x_refsource_CONFIRM
https://github.com/jbaines-r7/badblood
x_refsource_MISC
https://www.rapid7.com/blog/post/2022/01/11/cve-2021-2003...
x_refsource_MISC

EPSS Score

94% chance of being exploited in the next 30 days.

CVSS V3.1

Score:
9.8
Severity:
CRITICAL
Confidentiality:
High
Integrity:
High
Availability:
High
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
None
Scope:
Unchanged

Timeline

  • 🟡

    Public PoC available

  • 💰

    Used in Ransomware

  • 👾

    Exploit known to exist

  • 🦅

    CISA Reported

  • Vulnerability published

  • Vulnerability Reserved

.