An epidemic of cyberattacks on open-source software has mounted in recent months, making clear how uniquely difficult it is to protect the publicly available code, from both a policy and a technical perspective, that serves as the foundation for so much of the digital world.

While open-source software security got a boost in attention under President Joe Biden — whose administration grappled with the fallout from the potentially catastrophic Log4j flaw that emerged in 2021 — a number of open-source experts say that government protection efforts have suffered setbacks under President Donald Trump. Many also say companies that heavily rely on open-source software, which is basically all of them, haven’t shouldered enough of the responsibility for safeguarding it.

“What we’re seeing is years of lack of investment sustainment in open-source software that is finally starting to catch up to us, where it seems like every week there’s a new supply chain compromise,” said Jack Cable, who held a role at the Cybersecurity and Infrastructure Security Agency where he worked on open-source security before departing under Trump.

The advancements of frontier artificial intelligence models stand to exacerbate the risk further, while simultaneously illustrating what makes defending open source difficult: Project Glasswing said shortly after its announcement that it had uncovered 6,202 high- or critical-severity vulnerabilities in a scan of more than 1,000 open-source projects, but that it had disclosed only 502 of them to open-source project maintainers and only 75 had been patched as of May 22 (albeit some due to typical patching lagtimes).

At the same time, there are questions about how much the government can help, even as overseas governments seek to focus on open-source security.

The evolution of open-source risk 

There are a series of factors contributing to the current threat to open-source software, experts say.

One is simply that attackers go to the area where they can get the highest return on their work. Compromising open-source software gives them the chance to get into the supply chain and exploit additional targets.

“Twenty years ago, open source was still fairly niche,” said Æva Black, who also worked on open-source security at CISA but left when Trump came back into power. “The potential blast radius if you managed to compromise open source was relatively small, because back then the world didn’t run on open source. Now almost everything runs on open source,” she said, from modern cars to satellites.

Another part is the nature of open-source software itself.

“It’s a symptom [of having] lots of open source [that] is a little bit under-maintained or not cared for enough, so that we spend too little effort and money and infrastructure on them,” said Daniel Stenberg, who is the creator and maintainer of cURL, a popular open-source project. “Lots of open source is being maintained by small teams, lots of volunteers, and I think that that’s a tough situation.”

That doesn’t mean the maintainers are to blame, Stenberg said. The companies that rely on open-source need to be diligent about using it, Black said.

“What we’re seeing in that realm right now is not new; it is more advanced and far more widespread,” she said. “The problem remains that companies who use open source — because open source is by far the most efficient way to collaborate on non-product value features — most companies are not implementing a responsible and safe utilization pathway.”

Open-source projects lack a systematic way to handle coordinated vulnerability disclosures, unlike companies or industry groups with formal processes, said Dan Lorenc, CEO and co-founder of Chainguard. Project maintainers sometimes aren’t reachable, and those who are available are flooded with reports, many of them unverified findings from AI tools that waste their time without adding value..

Of course, some of those vulnerability reports turn out to be legitimate. “Mythos and AI models have contributed to an uptick in the number of vulnerabilities and things that we’re able to find” in open-source software, said Alex Zenia, chief technology officer for the cybersecurity company Edera.

All of that leaves more room for companies, non-profits and world governments to improve open-source security.

A moment of momentum

While open-source software security isn’t a new issue, the 2021 discovery of the Log4j flaw sounded alarms within the cybersecurity community. Jen Easterly, then the director of CISA, called it “one of the most serious I’ve seen in my entire career, if not the most serious,” with the potential to affect hundreds of millions of devices given the ubiquitous nature of the popular open-source logging library.

A year later, the Cyber Safety Review Board released its report on the incident, concluding that swift action from industry and government averted a disaster. But the incident “called attention to security risks unique to the thinly-resourced, volunteer-based open source community,” it wrote. “This community is not adequately resourced to ensure that code is developed pursuant to industry-recognized secure coding practices and audited by experts.”

The U.S. government actions after included some steps focused specifically on open-source software such as creation of the Open-Source Software Security Initiative and hires of well-regarded open-source security experts at CISA such as Black, but also some steps that could be applied more generally and still help with open-source security, such as greater promotion of secure-by-design, memory-safe languages and software bills of materials (SBOMs).

Some of the Biden administration work on open-source security started before Log4j, such as provisions from an executive order he issued in 2021 that directed CISA along with the Office of Management and Budget and General Services Administration to issue guidance to agencies. 

The administration’s 2023 cybersecurity strategy also stepped into the long, thorny discussions over software liability, with a mention of open-source security: “Responsibility must be placed on the stakeholders most capable of taking action to prevent bad outcomes, not on the end-users that often bear the consequences of insecure software nor on the open-source developer of a component that is integrated into a commercial product.“ The Biden administration always indicated that addressing software liability would take a prolonged battle ahead.

Under Trump, many of the Biden administration’s efforts have languished. CISA’s splashy hires on open-source are gone, including Black, Tim Pepper and Anjana Rajan. Also departed are leading figures on secure-by-design and SBOMs, with CISA personnel cutbacks slicing deep. 

No one has seen any sign that the national cyber director-led Open-Source Software Security Initiative is active, with few participants remaining in government today. The Trump administration cyber strategy doesn’t mention open-source.

“The loss of open-source experts at CISA “is unfortunate, and it will be hard for the government to try to rebuild capacity, but I do think now more than ever CISA has a core role to play to secure open source software,” Cable said.

The pressure is mounting

It’s not that the issue is getting zero attention from those in a position to make a difference. Nick Andersen, the acting director of CISA, said last month that open-source security was an area of particular concern for him.

Andersen responded to concerns about CISA staffing levels on open-source security and spoke more broadly on the topic in a statement to CyberScoop.

“As artificial intelligence and other technologies have the power to transform how vulnerabilities are discovered and exploited, CISA recognizes that the open source software (OSS) that underpins much of the nation’s critical infrastructure will need to be hardened,” he said. “CISA actively collaborates with our partners on shared priorities, including OSS security, to ensure time and resources are spent where they matter the most.  We have an immensely talented team, but are also accelerating our hiring in critical areas, to strengthen the nation’s defenses against cyber threats.”

The Office of the National Cyber Director did not respond to requests for comment.

There’s been some activity on Capitol Hill, too. The Securing Open Source Software Act, which Cable worked on during a stint as a Senate staffer, would direct CISA and other agencies to take actions to mitigate open-source software security risks, but the legislation has stalled since its introduction in 2022. A portion of the bill, however, was included in the Department of Homeland Security funding law Trump signed in April, directing CISA to brief Congress on the value of establishing something like an open source program office, which some companies use to manage open source within a given firm.

Senate Intelligence Committee Chairman Tom Cotton, R-Ark., has pushed the executive branch to improve its awareness of foreign adversaries playing roles in open-source software used by national security-focused agencies.

The annual defense policy bill in the House calls on the Defense Department’s chief information officer to report to Congress on a plan to secure open-source software supply chains, saying lawmakers are “concerned that the Department lacks sufficient visibility into the origins, maintenance, and security of OSS applications and software dependencies.”

That defense authorization bill language is “really beneficial, and I think it signals acknowledgement of this changing of culture” around open-source security risks, said Hayden Smith, founder of HuntedLabs, whose company won a contract with the Space Development Agency on supply chain security — agency work that the defense bill singled out.

“The report language is the first time the Hill is trying to get a true handle on foreign influence in open source code where they have oversight,” he said, saying it was a “piece of the puzzle” along with Cotton’s letter and a memo from Secretary of Defense Pete Hegseth last year about foreign influence in the Pentagon supply chain. “It’s good and would trickle down into everyone who provides software to the department.”

Zenia, though, believes trying to isolate China from open-source systems isn’t in and of itself a good idea. 

“I don’t think that that makes a lot of sense, because they’re actually pretty good things that people contribute to open source,” she said. “Not everyone is malicious, and what are we going to do, spy on every single open source maintainer?” It’s more about doing things like making sure that highly-classified systems are set up in a separate way, she said.

Europe is also taking action to secure open-source software that the United States doesn’t seem ready or willing to do right now. Germany, for instance, devotes grants to the security of open-source projects, although Stenberg pointed out that sometimes money doesn’t equate to maintainers being able to fix flaws more quickly, depending on the project’s size.

The Cyber Resilience Act (CRA) adopted by the Council of the European Union in 2024 could offer another road on open-source security. The CRA requires those who use open-source software products as part of any commercial activity to take certain security measures. 

Black said that when she was at CISA, there were discussions between the agency and European counterparts about finding compatible ideas on open-source security, but that momentum died with the Trump administration.

But “Europe kept rolling, and now has in place a new legal framework that is set to really reshape open-source security for potentially the whole world, but certainly for anyone who wants to work with Europe on open source,” she said.

Lorenc recently wrote that “open source isn’t governable.” He said an organization like a neutral nonprofit, possibly using some government funding, should take responsibility for things like coordinating vulnerability disclosure into one pipeline. He also said there needs to be one authority in charge of “forking” — that is, taking a project and assigning stewardship elsewhere — when a maintainer isn’t responsive to vulnerabilities. 

There are differing opinions on how much past government warnings, advisories and guidance have helped. Smith gave some credit to government agencies that “have all responded to open source attacks using the means they have.”

Stenberg said that “I don’t think they make any big dent at all in the big scheme of things.” They might get some attention initially, “then two years later we all forgot about them, and they actually didn’t change much.”

Ideally, everyone could get on the same page, Zenia said. “The best way to do this is if people actually collaborated on a global scale on some sort of regulation around this, but that seems nearly impossible at the current moment,” she said. (The United Nations’ Open Source Week runs all this week.)

But if there’s an upside to the spate of attacks on open-source software, it’s the energy it gives to how better to secure it, Lorenc said, invoking the political saying to never let a good crisis go to waste.

“Everyone knows the industry has to change,” he said. “This is a really good crisis, and the right things are happening in the right places, and organizations are rethinking their culture around software development, and they know what they have to do. It’s just something that’s never been top of the priority list for the last 10 years. Now it is, and they’re doing it, and it’s, ‘Can we do it fast enough?’”