In the ever-evolving landscape of Linux security, Canonical’s bold move to replace the venerable sudo command with a Rust-based alternative in Ubuntu 25.10 has hit a significant snag. Just weeks after the release of the ‘Questing Quokka’ distribution, multiple vulnerabilities have been uncovered in sudo-rs, raising questions about the rush to adopt memory-safe languages for core system utilities.

Ubuntu 25.10, launched in October 2025, marked a pivotal shift by making sudo-rs the default implementation of sudo, as announced by Canonical. This rewrite, developed in partnership with the Trifecta Tech Foundation, aimed to enhance memory safety and reduce vulnerabilities inherent in the original C-based sudo. According to a blog post on Ubuntu’s official site, the update was part of broader security enhancements including TPM-backed full disk encryption and post-quantum cryptography.

The Promise of Rust in System Tools

Industry experts initially praised the transition. As reported by It’s FOSS, the switch to sudo-rs was seen as a step toward eliminating entire classes of security bugs, with memory safety being a key selling point. Jon Seager, VP of Engineering at Canonical, highlighted in an X post from Ubuntu’s account that this made Ubuntu the first major distribution to adopt sudo-rs by default.

However, the optimism was short-lived. On November 10, 2025, Ubuntu issued a security notice, USN-7867-1, detailing vulnerabilities in sudo-rs. Phoronix reported that one critical issue involves the potential leakage of partially typed passwords if the sudo process times out or is killed, a flaw that could expose sensitive information in multi-user environments.

Vulnerabilities Exposed: A Closer Look

Further details from Ubuntu’s security notices reveal two primary issues: local disclosure of partially typed passwords and an authentication bypass under specific conditions. These were discovered shortly after the release, prompting swift patches. As noted in a post on X by Phoronix on November 11, 2025, the problems underscore the challenges of transitioning to new implementations, even in supposedly safer languages like Rust.

The timing is particularly ironic given the release’s focus on security. OMG! Ubuntu earlier explained that sudo-rs was chosen for its improved security profile, yet these bugs highlight that no code is immune to errors. Developers from the sudo-rs project acknowledged the issues, with fixes rolled out in updates for Ubuntu 25.10 users.

Industry Reactions and Broader Implications

Reactions on X have been mixed. A post from The Lunduke Journal in May 2025 criticized the rewrite, questioning what new features sudo-rs brought beyond ‘absolutely nothing’ compared to the original. More recently, sysxplore’s X update on October 12, 2025, listed sudo-rs as part of Ubuntu’s Rust-heavy updates, including coreutils replacements, which now face scrutiny amid these vulnerabilities.

Experts warn this could impact Ubuntu’s reputation as a secure platform. According to WebProNews in September 2025, the move was intended to influence other distributions, but flaws might deter adopters. Canonical’s response, as per their blog on Canonical’s site, emphasizes ongoing commitment to Rust for long-term benefits in Ubuntu 26.04 LTS.

Technical Breakdown of the Flaws

Diving deeper, the password leak vulnerability stems from how sudo-rs handles input buffering. Unlike the original sudo, which securely erases passwords from memory, sudo-rs failed to fully obscure them during interruptions, per LinuxSecurity advisories. This could allow malicious actors with local access to recover partial credentials, a risk amplified in shared systems.

A second flaw involves authentication logic, potentially allowing unauthorized privilege escalation if exploited correctly. Ubuntu’s advisory, echoed in an X post by LinuxSecurity Live Advisory Updates on November 11, 2025, urges immediate updates to mitigate these risks, affecting not just desktops but servers running the distribution.

Canonical’s Response and Patch Rollout

Canonical acted quickly, releasing patches via standard update channels. As detailed in How-To Geek on October 9, 2025, the initial release touted sudo-rs as a ‘huge deal’ for security, but post-vulnerability, the company has reinforced its testing processes. Jon Seager addressed community feedback in a video shared on X by Ubuntu in September 2025, acknowledging both supportive and critical comments.

The incident has sparked debates on Rust’s role in system software. While StartupNews praised the memory safety benefits for Ubuntu 26.04, critics like those on X point to this as evidence that rewrites introduce new risks, potentially offsetting gains from eliminating C-based vulnerabilities.

Lessons for Linux Ecosystem

Beyond Ubuntu, this event highlights broader challenges in adopting Rust for core tools. The New Stack noted in its coverage of Ubuntu 25.10 that while innovations like GNOME 49 and Linux Kernel 6.17 are impressive, security hiccups in sudo-rs could disrupt user trust.

Looking ahead, Canonical plans to refine sudo-rs for the upcoming LTS release. As per Neowin in September 2025, the project is ‘coming together nicely,’ but these vulnerabilities serve as a reminder that thorough auditing is essential. Industry insiders suggest increased community involvement in testing Rust rewrites to prevent similar issues.

Impact on Users and Future Directions

For Ubuntu 25.10 users, the advice is clear: apply updates promptly. Techzine Global reported the distribution’s Rust-based tools as a first for Linux desktops, but security patches are now critical to maintain integrity.

Ultimately, this episode underscores the double-edged sword of innovation in open-source software. While Rust promises safer code, the sudo-rs vulnerabilities in Ubuntu 25.10 illustrate that implementation matters as much as the language itself, setting the stage for more rigorous developments in future releases.