It's time to patch your SonicWall SMA 100 series appliances again!
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 +1 in the same advisory: …20043 | 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 group max | 25% |
| — |
Full article311 words · extracted from helpnetsecurity.com · click to collapse
SonicWall has fixed a handful of vulnerabilities affecting its SMA 100 series appliances and is urging organizations to implement the patches as soon as possible.
Although there’s currently no evidence of these bugs being exploited in active attacks, threat actors have been known to target these appliances in the past by leveraging known and zero-day vulnerabilities.
About the vulnerabilities
The patched vulnerabilities, which were reported by Jake Baines of Rapid7 and Richard Warren of NCC Group, received incremental identifiers from CVE-2021-20038 up to CVE-2021-20045.
“The most severe of these flaws are a set of unauthenticated heap- and stack-based buffer overflow vulnerabilities,” notes Claire Tills, senior research engineer at Tenable.
“CVE-2021-20038 covers a single vulnerability and received a CVSSv3 score of 9.8, while CVE-2021-20045 covers multiple vulnerabilities, the bundle received at CVSSv3 score of 9.4. CVE-2021-20038 is the result of using strcat() function when handling environment variables from the HTTP GET method used in the SMA SSLVPN Apache httpd server. CVE-2021-20043 is also a heap-based buffer overflow and it received a CVSSv3 score of 8.8, but it requires authentication to exploit. For all three of these CVEs, successful exploitation would result in code execution as the ‘nobody’ user in the SMA100 appliance.”
More specific details about the flaws have been made available by SonicWall’s PSIRT.
The vulnerabilities affect the whole SMA (Secure Mobile Access) 100 series, i.e., SMA 200, 210, 400, 410 and 500v appliances (both physical and virtual) running various firmware versions. SMA 100 series appliances with WAF enabled are also impacted by the majority of these vulnerabilities.
Organizations are advised to upgrade to firmware version 10.2.0.9-41sv or 10.2.1.3-27sv, and the company also urges users who still use firmware versions 9.0.0.x to upgrade to newer versions, because the former is no longer supported.
UPDATE (January 12, 2022, 01:05 a.m. PT):
Rapid7 researcher Jake Baines has shared the vulnerabilities’ technical details.
Text extracted automatically; images, tables and formatting may be missing. Original: https://www.helpnetsecurity.com/2021/12/09/sonicwall-sma-vulnerabilities/