Researchers at Tenable have identified a severe memory corruption vulnerability in Fluent Bit, an open-source logging utility integral to major cloud services. With over 3 billion downloads as of 2022 and an additional 10 million deployments daily, Fluent Bit is a cornerstone of cloud infrastructure used by prominent organisations such as VMware, Cisco, Adobe, Walmart, LinkedIn, and cloud giants like AWS, Microsoft, and Google Cloud.
The issue, dubbed "Linguistic Lumberjack" by Tenable, stems from how Fluent Bit's embedded HTTP server handles trace requests. The vulnerability can be exploited to cause denial of service (DoS), data leaks, or even remote code execution (RCE) in cloud environments.
"While vulnerabilities in major cloud providers like Azure, AWS, and GCP grab headlines, it's crucial to scrutinise the underlying technologies these services rely on," says Jimi Sebree, senior staff research engineer at Tenable. "Critical components like Fluent Bit, which are embedded in many cloud services, pose significant risks if compromised."
Tenable's researchers stumbled upon this flaw while investigating another security issue in a cloud service. They discovered they could access various internal metrics and logging endpoints of the cloud service provider, which included Fluent Bit instances. This cross-tenant data leakage revealed a more profound problem.
The vulnerability lies in the /api/v1/traces endpoint of Fluent Bit's monitoring API. The service fails to validate data types properly, allowing attackers to input non-string values that cause memory corruption. By manipulating these inputs, attackers can crash the service and leak sensitive data. Although exploiting this for RCE would require sophisticated, targeted efforts, the potential for harm remains high.
The bug affects Fluent Bit versions 2.0.7 through 3.0.3 and is tracked under CVE-2024-4323, with critical CVSS scores exceeding 9.5 out of 10. After reporting the issue on April 30, Fluent Bit's developers promptly addressed it by validating input data types in the problematic endpoint. The fix was implemented in the project's main branch on GitHub by May 15.
Organisations using Fluent Bit are strongly advised to update their software to the latest version immediately. Alternatively, administrators should review and restrict access to Fluent Bit's monitoring API to authorised users only, or disable it entirely if feasible.
The discovery of this vulnerability accentuates the importance of scrutinising not just the cloud services themselves but also the foundational technologies they depend on. Ensuring the security of tools like Fluent Bit is vital for maintaining the integrity of cloud environments across industries.
A new strain of ransomware known as BlackCat's Sphynx has recently been discovered by cybersecurity researchers at Microsoft. It has gained notice because it incorporates advanced hacking tools like Impacket and RemCom. This finding highlights the increasing sophistication and power of current ransomware attacks, creating concerns for both individuals and companies.
A new strain of ransomware known as BlackCat's Sphynx has recently been discovered by cybersecurity researchers at Microsoft. It has gained notice because it incorporates advanced hacking tools like Impacket and RemCom. This finding highlights the increasing sophistication and power of current ransomware attacks, creating concerns for both individuals and companies.
Impacket, an open-source collection of Python classes, enables the manipulation of network protocols and facilitates the creation of network-aware tools. It has legitimate uses in areas like network testing and penetration testing but can be weaponized by threat actors to infiltrate systems. RemCom, on the other hand, is a tool that grants remote access and control over compromised systems, allowing hackers to execute arbitrary commands.
Microsoft's analysis reveals that BlackCat's Sphynx leverages these tools to infiltrate networks, escalate privileges, and finally deploy ransomware to encrypt victims' data. The combination of these powerful tools amplifies the threat potential, as it grants attackers multiple avenues to compromise systems and ensure the success of their ransom demands.
The implications of this discovery extend beyond the immediate threat posed by BlackCat's Sphynx ransomware. The integration of well-established tools like Impacket and RemCom indicates an evolution in the tactics and techniques employed by ransomware operators. This also highlights the importance of organizations and individuals staying updated on the latest cybersecurity threats and fortifying their defenses against emerging attack vectors.
As ransomware attacks continue to surge and become increasingly sophisticated, cybersecurity experts stress the significance of a multi-layered defense strategy. Regularly updating software, educating users about phishing and social engineering tactics, and implementing robust network segmentation are among the recommended measures to minimize the risk of falling victim to such attacks.
One of these zero-day vulnerabilities is of remote code executive (RCE) type, affecting Windows HTML and Microsoft Office. Microsoft has surprisingly not yet released a patch for CVE-2023-36884, opting instead to provide configuration mitigation methods, despite this being a Patch Tuesday rollout. Microsoft has connected the exploitation of this vulnerability to the Russian cybercrime group RomCom, which is suspected to be acting in the interests of Russian intelligence.
According to Rapid7 vulnerability risk management specialist Adam Barnett, the RomCom gang has also been linked to ransomware assaults that have been directed at a variety of targets. More such security experts are raising concerns given the number of vulnerabilities and the multiple zero-days that they are coming across, regarding which they are warning Windows users to adopt the updated versions promptly. The Microsoft Security Update Guide contains a comprehensive list of the vulnerabilities fixed by the most recent Patch Tuesday release. Security professionals have, however, drawn attention to some of the more crucial ones.
According to Microsoft, “investigating reports of a series of remote code execution vulnerabilities impacting Windows and Office products. Microsoft is aware of targeted attacks that attempt to exploit these vulnerabilities by using specially-crafted Microsoft Office documents.”
While this vulnerability is still unpatched, Microsoft says it will “take the appropriate action to help protect our customers” ones they are done with the investigations. However, speculations claims that this will happen via an out-of-band security update rather than leaving an actively exploited zero-day up for patch for next month’s Patch Tuesday rollout. Microsoft directs users to a threat intelligence blog article that offers workaround mitigations in the meantime.
This flaw is a Windows MSHTML platform elevation of privilege vulnerability that is being exploited. The zero-day flaw exploits the MSHTML core Windows components, that are used to produce content like HTML.
According to Kev Breen, director of cyber threat research at Immersive Labs, “This is not limited to browsers.” He warns, “other applications like Office, Outlook, and Skype also make use of this component.” It is likely that the attack vectors would include typical suspects—a malicious document attached to an email or a malicious website or web page. . “This vulnerability would likely be used as an initial infection vector[…]allowing the attacker to gain code execution in the context of the user clicking the link or opening the document,” says Breen.
Eran Jacob, team leader of the security research team at Otorio, and Roni Gavrilov, security researcher, warn that the vulnerabilities are critical as they can be used to exploit thousands of industrial Internet of Things (IIoT) devices and networks in a variety of sectors, even though they affect devices from only three vendors, namely Sierra Wireless AirLink, Teltonika Networks RUT, and InHand Networks InRouter.
"Breaching of these devices can bypass all of the security layers in common deployments, as IIoT devices are commonly connected both to the Internet and the internal OT network[…]It also raises additional risk for propagation to additional sites through the built-in VPN," the researchers said.
The researchers added that in case the attackers acquire a direct connection to the internet OT environment, it may further impact production and pose safety risks for users in their virtual environment.
Attackers can also use a variety of vectors to take advantage of the flaws, according to the researchers, including compromising devices in the production network to enable unauthorized access and control with root privileges, gaining root access through a reverse shell, and using compromised devices to exfiltrate sensitive data and carry out actions like shutdown.
Multiple devices can connect to the Internet using a cellular network thanks to an industrial cellular router. According to the researchers, these routers are frequently utilized in industrial environments like factories or oil rigs where typical wired Internet connections would not be viable or dependable.
"Industrial cellular routers and gateways have become one of the most prevalent components in the IIoT landscape[…]They offer extensive connectivity features and can be seamlessly integrated into existing environments and solutions with minimal modifications," Gavrilov wrote in the report.
In order to give clients remote management, scalability, analytics, and security across their OT networks, vendors of these devices use cloud platforms. The researchers further noted that they discovered a number of vulnerabilities that "pertain to the connection between IIoT devices and cloud-based management platforms," which is, in some cases, enabled by default.
"These vulnerabilities can be exploited in various scenarios, affecting devices that are both registered and unregistered with remote management platforms[…]Essentially, it means that there are security weaknesses in the default settings of certain devices' connectivity to cloud-based management platforms, and these weaknesses can be targeted by attackers," they said.
Researchers have provided vendors of these devices as well as OT network administrators with a number of mitigation measures. They recommended that OT network managers uninstall any inactive cloud features if they are not actively using the router for cloud management in order to avoid device takeovers and minimize the attack surface.
Administrators can also restrict direct connection from IIoT devices to routers because built-in security mechanisms like firewalls and VPN tunnels lose their effectiveness after being compromised, according to the researchers.
"Adding separate firewall and VPN layers can assist with delimitering and reduce risks from exposed IIoT devices used for remote connectivity," Gavrilov added in the report.