CVE-2023-44221

Written by: Josh Goddard, Zander Work, Dimiter Andonov Introduction Google Threat Intelligence Group (GTIG) has identified an ongoing campaign by a suspected financially-motivated threat actor we track as UNC6148, targeting fully patched end-of-life SonicWall Secure Mobile Access (SMA) 100 series appliances. GTIG assesses with high confidence that UNC6148 is leveraging credentials and one-time password (OTP) seeds stolen during previous intrusions, allowing them to regain access even after organizations have applied security updates. Evidence for the initial infection vector was limited, as the actor's malware is designed to selectively remove log entries, hindering forensic investigation; however, it is likely this was through the exploitation of known vulnerabilities. In this new wave of activity, the actor has deployed a previously unknown persistent backdoor/user-mode rootkit, which GTIG tracks as OVERSTEP. Based on findings from Mandiant Incident Response engagements, our analysis shows this malware modifies the appliance's boot process to maintain persistent access, steal sensitive credentials, and conceal its own components. GTIG assesses with moderate confidence that UNC6148 may have used an unknown zero-day remote code execution vulnerability to deploy OVERSTEP on opportunistically targeted SonicWall SMA appliances. GTIG assesses with moderate confidence that UNC6148's operations, dating back to at least October 2024, may be to enable data theft and extortion operations, and possibly ransomware deployment. An organization targeted by UNC6148 in May 2025 was posted to the "World Leaks" data leak site (DLS) in June 2025, and UNC6148 activity overlaps with publicly reported SonicWall exploitation from late 2023 and early 2024 that has been publicly linked to the deployment of Abyss-branded ransomware (tracked by GTIG as VSOCIETY). Given the risk of recompromise using previously stolen credentials, organizations should follow the recommendations within this...

Another day, another edge device being targeted - it’s a typical Thursday!In today’s blog post, we’re excited to share our previously private analysis of the now exploited in-the-wild N-day vulnerabilities affecting SonicWall’s SMA100 appliance. Over the last few months, our client

Another day, another edge device being targeted - it’s a typical Thursday!In today’s blog post, we’re excited to share our previously private analysis of the now exploited in-the-wild N-day vulnerabilities affecting SonicWall’s SMA100 appliance. Over the last few months, our client

CISA has added two new vulnerabilities to its Known Exploited Vulnerabilities Catalog, based on evidence of active exploitation. CVE-2024-38475 Apache HTTP Server Improper Escaping of Output Vulnerability CVE-2023-44221 SonicWall SMA100 Appliances OS Command Injection Vulnerability These types of vulnerabilities are frequent attack vectors for malicious cyber actors and pose significant risks to the federal enterprise. Binding Operational Directive (BOD) 22-01: Reducing the Significant Risk of Known Exploited Vulnerabilities established the Known Exploited Vulnerabilities Catalog as a living list of known Common Vulnerabilities and Exposures (CVEs) that carry significant risk to the federal enterprise. BOD 22-01 requires Federal Civilian Executive Branch (FCEB) agencies to remediate identified vulnerabilities by the due date to protect FCEB networks against active threats. See the BOD 22-01 Fact Sheet for more information. Although BOD 22-01 only applies to FCEB agencies, CISA strongly urges all organizations to reduce their exposure to cyberattacks by prioritizing timely remediation of Catalog vulnerabilities as part of their vulnerability management practice. CISA will continue to add vulnerabilities to the catalog that meet the specified criteria.

SonicWall has revealed that two now-patched security flaws impacting its SMA100 Secure Mobile Access (SMA) appliances have been exploited in the wild. The vulnerabilities in question are listed below - CVE-2023-44221 (CVSS score: 7.2) - Improper neutralization of special elements in the SMA100 SSL-VPN management interface allows a remote authenticated attacker with administrative privilege to