Two security researchers have detailed how they chained three Samsung vulnerabilities, including a flaw in the Bixby virtual assistant, to achieve remote system-level compromise on Galaxy smartphones. Dimitrios Valsamaras of Microsoft and Ken Gannon of Mobile Hacking Lab demonstrated the exploit at Pwn2Own Ireland in October 2025, earning $50,000 for hacking a Samsung Galaxy S25, and presented the full technical breakdown at Black Hat.
The attack begins with social engineering: a victim clicks a malicious link delivered through ads or a messaging app. That click triggers CVE-2025-21079, forcing the preloaded Samsung Members app to connect to an attacker-controlled site. The malicious site then makes Samsung Members open the Samsung Account app, which is used to authenticate users to Samsung services.
From there, CVE-2025-58486 forces Samsung Account to reach out to a second attacker-controlled website, which exploits a cross-site scripting flaw, CVE-2025-58487, to make Samsung Account launch Bixby. This step works because Samsung Account holds a special permission needed to reach a specific internal entry point in Bixby, described by Gannon as a “side entrance” that Samsung Account happens to hold the key to.
Abusing Bixby’s Capsule architecture
The final stage targets Bixby’s Capsules, hidden background services inside apps that function like mini internal servers. Normally, only Bixby itself is permitted to communicate with a Capsule to carry out voice commands. By reverse-engineering this infrastructure, the researchers found a way to force Bixby to invoke Capsules maliciously, enabling data exfiltration and ultimately system-level privileges, the highest access level available on a stock consumer Android device. With system permissions in hand, the researchers showed they could achieve remote code execution and fully take over the phone.
The chain was successfully reproduced on Samsung Galaxy S25, S24, and Flip 7 devices.
Patch status
Samsung began fixing the issues in the weeks following Pwn2Own. A November patch to the Samsung Members app blocked the initial trigger via browser or messaging app, while December patches addressed the Samsung Account flaws. The researchers noted the chain still works on older, unpatched devices, though it requires all targeted apps, Members, Account, and Bixby, to be installed. These come preloaded on flagship models, but it is unclear whether budget devices carry the same app set. Samsung had not responded to a request for comment at the time of reporting.