Cybersecurity researchers on Wednesday disclosed three severe security vulnerabilities impacting SolarWinds products, the most severe of which could have been exploited to achieve remote code execution with elevated privileges.
Two of the flaws (CVE-2021-25274 and CVE-2021-25275) were identified in the SolarWinds Orion Platform, while a third separate weakness (CVE-2021-25276) was found in the company’s Serv-U FTP server for Windows, said cybersecurity firm Trustwave in a technical analysis.
None of the three vulnerabilities are believed to have been exploited in any “in the wild” attacks or during the unprecedented supply chain attack targeting the Orion Platform that came to light last December.
The two sets of vulnerabilities in Orion and Serv-U FTP were disclosed to SolarWinds on December 30, 2020, and January 4, 2021, respectively, following which the company resolved the issues on January 22 and January 25.
It’s highly recommended that users install the latest versions of Orion Platform and Serv-U FTP (15.2.2 Hotfix 1) to mitigate the risks associated with the flaws. Trustwave said it intends to release a proof-of-concept (PoC) code next week on February 9.
Complete Control Over Orion
Chief among the vulnerabilities uncovered by Trustwave includes improper use of Microsoft Messaging Queue (MSMQ), which is used heavily by the SolarWinds Orion Collector Service, thereby allowing unauthenticated users to send messages to such queues over TCP port 1801 and eventually attain RCE by chaining it with another unsafe deserialization issue in the code that handles incoming messages.
“Given that the message processing code runs as a Windows service configured to use LocalSystem account, we have complete control of the underlying operating system,” Trust researcher Martin Rakhmanov said.
The patch released by SolarWinds (Orion Platform 2020.2.4) addresses the bug with a digital signature validation step that’s performed on arrived messages to ensure that unsigned messages are not processed further, but Rakhmanov cautioned that the MSMQ is still unauthenticated and allows anyone to send messages to it.
The second vulnerability, also found in the Orion Platform, concerns the insecure manner in which credentials of the backend database (named “SOLARWINDS_ORION”) is stored in a configuration file, resulting in a local, unprivileged user take complete control over the database, steal information, or even add a new admin-level user to be used inside SolarWinds Orion products.
Lastly, a flaw in SolarWinds Serv-U FTP Server 15.2.1 for Windows could allow any attacker that can log in to the system locally or via Remote Desktop to drop a file that defines a new admin user with full access to the C:\ drive, which can then be leveraged by logging in as that user via FTP and read or replace any file on the drive.
U.S. Department of Agriculture Targeted Using New SolarWinds Flaw
News of the three vulnerabilities in SolarWinds products comes on the heels of reports that alleged Chinese threat actors exploited a previously undocumented flaw in the company’s software to break into the National Finance Center, a federal payroll agency inside the U.S. Department of Agriculture.
This flaw is said to be different from those that were abused by suspected Russian threat operatives to compromise SolarWinds Orion software that was then distributed to as many as 18,000 of its customers, according to Reuters.
In late December, Microsoft said a second hacker collective might have been abusing the IT infrastructure provider’s Orion software to drop a persistent backdoor called Supernova on target systems by taking advantage of an authentication bypass vulnerability in the Orion API to execute arbitrary commands.
SolarWinds issued a patch to address the vulnerability on December 26, 2020.
Last week, Brandon Wales, acting director of the U.S. Cybersecurity and Infrastructure Agency (CISA), said nearly 30% of the private-sector and government agencies linked to the intrusion campaign had no direct connection to SolarWinds, implying that the attackers used a variety of ways to breach target environments.
The overlap in the twin espionage efforts notwithstanding, the campaigns are yet another sign that advanced persistent threat (APT) groups are increasingly focusing on the software supply chain as a conduit to strike high-value targets such as corporations and government agencies.
The trust and ubiquity of software such as those from SolarWinds or Microsoft make them a lucrative target for attackers, thus underscoring the need for organizations to be on the lookout for potential dangers stemming from relying on third-party tools to manage their platforms and services.
