Attackers are actively targeting critical RCE in SonicWall Secure Mobile Access
Vulnerabilities mentionedAll →
| CVE | Vulnerability | CVSS | EPSS | Flags | Affected | Exposure | Published |
|---|---|---|---|---|---|---|---|
| CVE-2021-20038 | Unauthenticated Stack Buffer Overflow in SonicWall SMA 100 Appliances SonicWall SMA 100 series secure remote-access appliances contain an unauthenticated stack-based buffer overflow (CWE-121) in the appliance's network-facing interface, triggered by crafted requests sent to the device without any credentials. A remote attacker who triggers the overflow can execute arbitrary code on the appliance with the privileges of the affected service, gaining a foothold on an internet-facing VPN gateway that typically sits at the network edge. Any organization running an SMA 100 series appliance is affected, and because these appliances provide remote access to corporate networks, compromise can expose entire internal environments. Exploitation is confirmed in the wild: the flaw was added to CISA KEV on 2022-01-28 with known ransomware use, and EPSS assigns a 99.9% probability of exploitation within 30 days (100th percentile). No public proof-of-concept is catalogued in the provided data, but the KEV listing and EPSS score indicate active attacker interest. Do: Upgrade SMA 100 series appliances to firmware 10.0.7.2 or later per SonicWall's instructions, as required by the CISA KEV listing. Until patched, restrict internet exposure of the SMA portal and management interface to trusted sources where feasible. Because ransomware operators are known to exploit this flaw, review appliance logs for signs of compromise and monitor for unexpected account creation or traffic after patching. | 9.8 | 100% | KEV ransomware PoC ×2 |
| largetens of thousands of internet-exposed SMA 100 appliances (order of magnitude ~10,000-50,000 devices), plus a larger installed base used internally | |
| CVE-2021-20045 | A buffer overflow vulnerability in SMA100 sonicfiles RAC_COPY_TO (RacNumber 36) method allows a remote unauthenticated attacker to potentially execute code as t A buffer overflow vulnerability in SMA100 sonicfiles RAC_COPY_TO (RacNumber 36) method allows a remote unauthenticated attacker to potentially execute code as the 'nobody' user in the appliance. This vulnerability affected SMA 200, 210, 400, 410 and 500v appliances. NVD description · AI analysis pending | 9.8 | 25% |
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Full article361 words · extracted from securityaffairs.com · click to collapse
Threat actors are actively exploiting a critical flaw (CVE-2021-20038) in SonicWall’s Secure Mobile Access (SMA) gateways addressed in December.
Threat actors are actively exploiting a critical flaw, tracked as CVE-2021-20038, in SonicWall’s Secure Mobile Access (SMA) gateways addressed by the vendor in December.
The vulnerability is an unauthenticated stack-based buffer overflow that was reported by Jacob Baines, lead security researcher at Rapid7. The CVE-2021-20038 vulnerability impacts SMA 100 series appliances (including SMA 200, 210, 400, 410, and 500v) even when the web application firewall (WAF) is enabled.
A remote attacker can exploit the vulnerability to execute arbitrary code as the ‘nobody’ user in compromised SonicWall appliances.
In early December, security vendor SonicWall urged customers using SMA 100 series appliances to apply security patches that address multiple security vulnerabilities, some of which have been rated as critical.
The most severe vulnerabilities addressed by SonicWall are two critical stack-based buffer overflow vulnerabilities tracked as CVE-2021-20038 and CVE-2021-20045 respectively. A remote attacker can trigger the two vulnerabilities to potentially execute as the ‘nobody’ user in compromised appliances.
“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.” reads the advisory for the CVE-2021-20038 flaw.
The news of the exploitation of the issue in the wild was confirmed by the security firm NCC Group.
— Rich Warren (@buffaloverflow) January 24, 2022Some attempts itw on CVE-2021-20038 (SonicWall SMA RCE). Also some password spraying of default passwords from the past few days
Remember to update AND change default passwords 🙂 pic.twitter.com/WyDIXVKb4m
Experts also warned of some password spraying attacks attempting to compromise devices using default passwords.
The attacks spotted by the researchers don’t seem to be the result of a massive coordinated attack, some threat actors are only opportunistic attempts to trigger the flaw.
None of the observed attacks were successful.
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(SecurityAffairs – hacking, SonicWall Secure Mobile Access)
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