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CVE-2021-20038 is a critical stack-based buffer overflow vulnerability in SonicWall SMA 100 Series appliances, affecting SMA 200, 210, 400, 410, and 500v devices. The flaw resides in the SMA SSLVPN Apache httpd server, specifically in mod_cgi handling of environment variables associated with HTTP GET requests. The vulnerable code path concatenates environment-variable data into a single stack buffer using unsafe string handling with strcat, allowing memory corruption when attacker-controlled input exceeds the available buffer space. A remote unauthenticated attacker can trigger the overflow and potentially achieve code execution in the appliance context as the low-privilege "nobody" user. Affected firmware includes 10.2.0.8-37sv, 10.2.1.1-19sv, 10.2.1.2-24sv, and earlier versions.
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1 valid exploit after Mallory filtered fakes, detection scripts, and README-only repos.
Repository purpose: a Python-based SonicWall “Security Audit Toolkit” plus a Docker CTF-style lab that simulates and (in solutions) exploits two critical SonicWall CVEs. Top-level structure: - sonicwall_audit.py: main orchestrator CLI that runs modules (ssl, cve, auth, web) against a target https://<host>:<port>, writes JSON/text reports to reports/. - validate_cves.py: standalone deep validators for CVE-2021-20038 and CVE-2024-53704 using non-destructive behavioral checks. - modules/: implementation of auditors/validators and report generation. - lab/: docker-compose lab with two containers: - cve-2021-20038: Apache + deliberately vulnerable 32-bit CGI binary /usr/lib/cgi-bin/sslvpnclient (and symlinks portal/welcome/etc). Protections disabled (no canary, execstack, no PIE, ASLR disabled in entrypoint) to make stack overflow exploitation feasible. - cve-2024-53704: Flask/Gunicorn SSLVPN simulator on 4433 with vulnerable swap cookie deserialization (conditional HMAC verification). - lab/exploits/: skeleton exploit templates (incomplete). - lab/solutions/: working exploits. Exploit capabilities present: 1) CVE-2024-53704 (auth bypass via cookie forgery): Working exploit forges a base64-encoded JSON session cookie named swap with {username, authenticated:true} and omits sig_version so the server skips HMAC verification. It then accesses /virtual-office/ and /dashboard to retrieve the flag. 2) CVE-2021-20038 (stack buffer overflow -> RCE): Working exploit crafts a URL-encoded query string payload to overflow a 4096-byte stack buffer in the CGI handler (strcpy of QUERY_STRING). Payload includes a NOP sled, null-free 32-bit x86 Linux shellcode that runs /bin//sh -c "cat /root/flag.txt", padding to offset 4100, and an attacker-chosen return address into the sled. Output is returned in the HTTP response body. Important distinction: the main toolkit modules and CVE validators are primarily scanners/validators and explicitly avoid destructive exploitation; the actual exploitation code is confined to the lab solution scripts intended for the local practice environment.
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14 sources tracked across advisories, community write-ups, and news. New activity surfaces here as Mallory finds it.
A historical SonicWall SMA100 stack-based buffer overflow vulnerability mentioned as background on prior exploitation of SonicWall devices.
A stack-based buffer overflow vulnerability in SonicWall SMA100.
A memory corruption vulnerability in SonicWall SMA referenced as a possible prior exploitation path by UNC6148.
A known vulnerability in SonicWall SMA 100 series appliances that may allow remote attackers to gain unauthorized access.
Query your assets running an affected version, and investigate the blast radius.
Every observed campaign linking this CVE to a named adversary.
Malware families riding this exploit, with evidence and IOCs.
YARA, Sigma, Snort, and vendor rules, auto-deployed to your SIEM.
Cross-references every affected SKU, including bundled OEM variants.
Community discussion across Reddit, Mastodon, and other social sources.