Mardi 18 août 2026

zephyrproject zephyr

The Zephyr kernel validates the k_thread_join() and k_thread_abort() system calls (declared __syscall in include/zephyr/kernel.h) through thread_obj_validate() in kernel/thread.c. Its default switch branch is the access-denied path, taken when k_object_validate() returns -EPERM (the calling user thread was never granted access to the target thread object) or -EBADF (the supplied pointer is not a registered kernel object of the right type). That branch invoked K_OOPS(K_SYSCALL_VERIFY_MSG(ret, "access denied")), but K_SYSCALL_VERIFY_MSG treats a true expression as success; the non-zero error code ret therefore read as "verified OK", the kernel oops was never raised, and control fell through to CODE_UNREACHABLE. Because k_thread_join() and k_thread_abort() are system calls, an unprivileged user-mode thread (under CONFIG_USERSPACE) can reach this denial path directly by calling either syscall on a thread object it does not own. Instead of the offending thread being cleanly terminated, execution reaches __builtin_unreachable() while running in supervisor mode inside the syscall handler. On Clang builds CODE_UNREACHABLE emits an illegal-instruction trap, so a user thread can deterministically crash the kernel — a locally triggerable denial of service that escapes the userspace sandbox. On GCC builds the path is undefined behavior: the compiler may drop the return-value handling for thread_obj_validate(), so it can return an undefined bool; if that is false, the caller proceeds into the real k_thread_join()/k_thread_abort() implementation for a thread the user was never authorized to access, an access-control bypass. The fix changes the verification expression to ret == 0, so a denied (non-zero) result now correctly raises K_OOPS and terminates the offending caller.

alextselegidis plainpad

Plainpad through 1.1.1, fixed in commit d3823fc, contains a missing rate limiting vulnerability that allows unauthenticated attackers to send unbounded login requests to the POST /v1/sessions endpoint due to dead code in App\Http\Kernel.php that is never instantiated under the Laravel 11+ skeleton, leaving the API throttle configuration unattached to any route. Attackers can exploit this by sending unlimited credential attempts with no lockout or CAPTCHA enforcement, and additionally trigger CPU exhaustion by forcing repeated bcrypt comparisons on each request.

zephyrproject zephyr

The Sierra Wireless HL7800 cellular modem driver (drivers/modem/vendor_standalone/hl7800.c, located at drivers/modem/hl7800.c in v4.4.0 and earlier) parses AT responses with roughly twenty handlers that call net_buf_linearize(value, sizeof(value), *buf, 0, len) into a 128-byte stack buffer and then write value[out_len] = 0. Because net_buf_linearize() (lib/net_buf/buf.c) can return a count equal to its destination-length argument, a field that exactly fills the buffer makes the terminating NUL land one byte past the end, a single-byte out-of-bounds write into adjacent stack memory. The +KCELLMEAS cell-measurement handler on_cmd_atcmdinfo_rssi() is worse: it passed the wire length len as the destination size (net_buf_linearize(value, len, *buf, 0, len)), so a response line longer than 128 bytes overflows the value stack buffer with attacker-influenceable content. The line length comes from net_buf_findcrlf(), which accumulates bytes across the whole net_buf fragment chain and is not bounded to 128, so an over-long line reaches the defect. The data originates from the cellular modem over UART, driven by the network: operator-scan results, +CGCONTRDP IP/DNS info, socket indications, and +KCELLMEAS neighbour-cell reports. An attacker able to shape what the modem emits — a rogue base station, a compromised modem baseband, or a remote peer feeding oversized response framing — can drive a line past 128 bytes. The handlers run in the driver's RX thread in kernel context, so the corruption is kernel-side. The +KCELLMEAS path is a full stack buffer overflow whose worst case is code execution in kernel context and whose floor is a reliable crash; the remaining sites are single-byte NUL out-of-bounds writes. Exploitation requires the modem to emit an over-long AT response line, giving high attack complexity over an adjacent (cellular radio) vector. The fix passes sizeof(dst) - 1 (and correct explicit bounds for the IMSI and +KCELLMEAS sites) so the terminator always stays in bounds.

Apple iOS and iPadOS · Apple macOS · Apple tvOS · Apple visionOS

An out-of-bounds read was addressed with improved input validation. This issue is fixed in iOS 26.6.1 and iPadOS 26.6.1, macOS Sequoia 15.8, macOS Tahoe 26.6.2, tvOS 27, visionOS 27, watchOS 27. An app may be able to cause unexpected system termination or read kernel memory.

Apple iOS and iPadOS · Apple macOS · Apple tvOS · Apple visionOS

The issue was addressed with improved memory handling. This issue is fixed in iOS 26.6.1 and iPadOS 26.6.1, macOS Sequoia 15.8, macOS Tahoe 26.6.2, tvOS 27, visionOS 27, watchOS 27. An app may be able to cause unexpected system termination or corrupt kernel memory.

Apple iOS and iPadOS · Apple macOS · Apple tvOS · Apple visionOS

An information leakage was addressed with additional validation. This issue is fixed in iOS 18.7.10 and iPadOS 18.7.10, iOS 27 and iPadOS 27, macOS Golden Gate 27, tvOS 27, visionOS 27, watchOS 27. An app may be able to leak sensitive kernel state.