OPEN LINK ↗
// 1h agoSECURITY INCIDENT
Big Fish Exploits 37-Year OpenBSD Bug
Calif’s Big Fish research chains a 37-year-old shared-memory counter overflow with a kernel out-of-bounds write to achieve local privilege escalation and a root shell on OpenBSD. OpenBSD addressed the underlying issues in errata before the exploit’s publication.
// ANALYSIS
Big Fish shows how legacy integer assumptions can survive inside hardened operating systems—and how deterministic kernel allocation can turn small primitives into full compromise.
- –The exploit bypasses KARL, SMAP, and SMEP without requiring an information disclosure.
- –A signed 16-bit attachment counter wraps after repeated shared-memory activity, enabling a race-driven use-after-free.
- –A separate out-of-bounds write creates the control-flow primitive needed for kernel code execution.
- –The research exposes remaining hardening gaps around allocator and page-table randomization.
- –Its AI-security angle is secondary; the main lesson is that defense-in-depth still depends on eliminating entire vulnerability classes.
// TAGS
big-fishopenbsdsecurityresearchopen-source
DISCOVERED
1h ago
2026-10-16
PUBLISHED
3h ago
2026-10-16
RELEVANCE
5/ 10
AUTHOR
rs_rs_rs_rs_rs
