Five Eyes nations reveal 2021's fifteen most-exploited flaws

Malicious cyber actors go after 2021's biggest misses, spend less time on the classics

Security flaws in Log4j, Microsoft Exchange, and Atlassian's workspace collaboration software were among the bugs most frequently exploited by "malicious cyber actors" in 2021 , according to a joint advisory by the Five Eyes nations' cybersecurity and law enforcement agencies.

It's worth noting that 11 of the 15 flaws on the list were disclosed in 2021, as previous years' lists often found miscreants exploiting the older vulns for which patches had been available for years.

Of course, the US Cybersecurity and Infrastructure Security Agency (CISA) and friends note that malicious cyber actors have not stopped trying to exploit older flaws – but reckon those efforts are happening to a "lesser extent" than in the past.

In 2021 bad actors "aggressively targeted newly disclosed critical software vulnerabilities," according to the US, Australian, Canadian, New Zealand and UK cybersecurity authorities.

The Log4j vulnerability – tracked as CVE-2021-44228 and also called Log4Shell – tops the list. This doesn't mean it was the most exploited of the bunch — the list isn't a ranking in that sense — but it's the first bug detailed in the joint advisory.

As security teams worldwide undoubtedly remember, this flaw was discovered in mid-December and affects Apache's widely used open source logging framework. CISA director Jen Easterly called it the "most serious" vulnerability she's seen in her career. 

The remote code execution vulnerability allows attackers to submit a specially crafted request, which isn't validated by the code, and then take control of an infected system. Criminals can then steal data, deploy ransomware or conduct other nefarious activity — at truly staggering speed.

According to cybersecurity service provider Qualys, nearly one million exploitation attempts were made in 72 hours following the Log4j vulnerability disclosure in December 2021. Two months later, 30 per cent of Log4j instances apparently remained vulnerable to attack.

Just last month, cybersecurity firm Sophos warned that VMware's virtual desktop and applications platform continues to be a hot target for Log4j attacks – many of which are designed to drop crypto-mining malware on infected machines.

Data released this week by security firm LookingGlass suggested that the number of systems that could be exploited through Log4j vulnerabilities has increased. In early February, the company tracked about 55,000 potentially vulnerable assets, according to numbers shared with The Register. However, the "current collection" of Log4j-associated products indicates about 92,000 assets remain potentially vulnerable.

Microsoft Exchange bugs

The next group of vulnerabilities on the list affect Microsoft Exchange email servers, and are collectively known as ProxyLogon (CVE-2021-26855, CVE-2021-26858, CVE-2021-26857 and CVE-2021-27065) and ProxyShell (CVE-2021-34523, CVE-2021-34473 and CVE-2021-31207). When combined, these flaws allow miscreants to gain persistent access to credentials, files and mailboxes on the severs, and potentially compromise trust and identity across the network.

Although Microsoft patched these vulnerabilities a year ago, not all organizations have updated their Exchange email servers – so the bugs are still proving to be quite effective for crooks. 

Earlier this month, data security vendor Varonis Systems disclosed that a Hive ransomware group affiliate is exploiting these vulnerabilities to encrypt and exfiltrate data and threaten to publicly disclose the information if a ransom isn't paid.

There's also a separate Microsoft Exchange Server RCE vulnerability (CVE-2020-0688) on the list discovered back in 2020 that's not related to ProxyLogon or ProxyShell.

Atlassian, but make it 2021

Another one of the most-exploited flaws, tracked as CVE-2021-26084, affects Atlassian Confluence, and allows unauthenticated users to execute malicious code on vulnerable systems. 

"This vulnerability quickly became one of the most routinely exploited vulnerabilities after a [proof of concept] was released within a week of its disclosure," the joint advisory states. "Attempted mass exploitation of this vulnerability was observed in September 2021."

Readers shouldn't confuse that Atlassian flaw with the more recent buggy script that resulted in a two-week outage and deleted about 400 customers' data.

Learning from past mistakes?

While the joint advisory doesn't provide as much detail about the six other most-exploited bugs on the list, it does include a VMware vSphere RCE vuln (CVE-2021-21972) and a Zoho ManageEngine ADSelfService Plus RCE vuln (CVE-2021-40539) in the lineup.

The final three listed vulns were also "routinely" exploited in 2020, according to the security alert. These are an elevation of privilege vulnerability in Microsoft Netlogon Remote Protocol (CVE2020-1472), a path traversal flaw in Fortinet FortiOS and FortiProxy (CVE-2018-13379) and an arbitrary file reading flaw in Pulse Secure (CVE-2019-11510). 

"Their continued exploitation indicates that many organizations fail to patch software in a timely manner and remain vulnerable to malicious cyber actors," the security officials noted.

It's not too late to prepare to avoid finding your systems on next year's most-exploited list: patch early, and patch often. ®

Narrower topics

Other stories you might like

  • Lonestar plans to put datacenters in the Moon's lava tubes
    How? Founder tells The Register 'Robots… lots of robots'

    Imagine a future where racks of computer servers hum quietly in darkness below the surface of the Moon.

    Here is where some of the most important data is stored, to be left untouched for as long as can be. The idea sounds like something from science-fiction, but one startup that recently emerged from stealth is trying to turn it into a reality. Lonestar Data Holdings has a unique mission unlike any other cloud provider: to build datacenters on the Moon backing up the world's data.

    "It's inconceivable to me that we are keeping our most precious assets, our knowledge and our data, on Earth, where we're setting off bombs and burning things," Christopher Stott, founder and CEO of Lonestar, told The Register. "We need to put our assets in place off our planet, where we can keep it safe."

    Continue reading
  • Conti: Russian-backed rulers of Costa Rican hacktocracy?
    Also, Chinese IT admin jailed for deleting database, and the NSA promises no more backdoors

    In brief The notorious Russian-aligned Conti ransomware gang has upped the ante in its attack against Costa Rica, threatening to overthrow the government if it doesn't pay a $20 million ransom. 

    Costa Rican president Rodrigo Chaves said that the country is effectively at war with the gang, who in April infiltrated the government's computer systems, gaining a foothold in 27 agencies at various government levels. The US State Department has offered a $15 million reward leading to the capture of Conti's leaders, who it said have made more than $150 million from 1,000+ victims.

    Conti claimed this week that it has insiders in the Costa Rican government, the AP reported, warning that "We are determined to overthrow the government by means of a cyber attack, we have already shown you all the strength and power, you have introduced an emergency." 

    Continue reading
  • China-linked Twisted Panda caught spying on Russian defense R&D
    Because Beijing isn't above covert ops to accomplish its five-year goals

    Chinese cyberspies targeted two Russian defense institutes and possibly another research facility in Belarus, according to Check Point Research.

    The new campaign, dubbed Twisted Panda, is part of a larger, state-sponsored espionage operation that has been ongoing for several months, if not nearly a year, according to the security shop.

    In a technical analysis, the researchers detail the various malicious stages and payloads of the campaign that used sanctions-related phishing emails to attack Russian entities, which are part of the state-owned defense conglomerate Rostec Corporation.

    Continue reading
  • FTC signals crackdown on ed-tech harvesting kid's data
    Trade watchdog, and President, reminds that COPPA can ban ya

    The US Federal Trade Commission on Thursday said it intends to take action against educational technology companies that unlawfully collect data from children using online educational services.

    In a policy statement, the agency said, "Children should not have to needlessly hand over their data and forfeit their privacy in order to do their schoolwork or participate in remote learning, especially given the wide and increasing adoption of ed tech tools."

    The agency says it will scrutinize educational service providers to ensure that they are meeting their legal obligations under COPPA, the Children's Online Privacy Protection Act.

    Continue reading
  • Mysterious firm seeks to buy majority stake in Arm China
    Chinese joint venture's ousted CEO tries to hang on - who will get control?

    The saga surrounding Arm's joint venture in China just took another intriguing turn: a mysterious firm named Lotcap Group claims it has signed a letter of intent to buy a 51 percent stake in Arm China from existing investors in the country.

    In a Chinese-language press release posted Wednesday, Lotcap said it has formed a subsidiary, Lotcap Fund, to buy a majority stake in the joint venture. However, reporting by one newspaper suggested that the investment firm still needs the approval of one significant investor to gain 51 percent control of Arm China.

    The development comes a couple of weeks after Arm China said that its former CEO, Allen Wu, was refusing once again to step down from his position, despite the company's board voting in late April to replace Wu with two co-chief executives. SoftBank Group, which owns 49 percent of the Chinese venture, has been trying to unentangle Arm China from Wu as the Japanese tech investment giant plans for an initial public offering of the British parent company.

    Continue reading
  • SmartNICs power the cloud, are enterprise datacenters next?
    High pricing, lack of software make smartNICs a tough sell, despite offload potential

    SmartNICs have the potential to accelerate enterprise workloads, but don't expect to see them bring hyperscale-class efficiency to most datacenters anytime soon, ZK Research's Zeus Kerravala told The Register.

    SmartNICs are widely deployed in cloud and hyperscale datacenters as a means to offload input/output (I/O) intensive network, security, and storage operations from the CPU, freeing it up to run revenue generating tenant workloads. Some more advanced chips even offload the hypervisor to further separate the infrastructure management layer from the rest of the server.

    Despite relative success in the cloud and a flurry of innovation from the still-limited vendor SmartNIC ecosystem, including Mellanox (Nvidia), Intel, Marvell, and Xilinx (AMD), Kerravala argues that the use cases for enterprise datacenters are unlikely to resemble those of the major hyperscalers, at least in the near term.

    Continue reading

Biting the hand that feeds IT © 1998–2022