(calif.io) CVE-2026-7270: Root Privilege Escalation in FreeBSD via Kernel Memory Corruption in execve()
New critical LPE in FreeBSD: CVE-2026-7270 enables root access via a one-character error in `execve()` kernel handling. Exploit targets `sshd-session` with `LD_PRELOAD` injection through a race condition.
In brief - CVE-2026-7270 is a local privilege escalation flaw in FreeBSD (since 2013) caused by a sign error in `execve()` memory handling. Attackers can corrupt kernel memory during shebang script execution, inject `LD_PRELOAD`, and gain root via `sshd-session`. Affects default installations.
Technically - The bug in `sys/kern/kern_exec.c` (`exec_args_adjust_args`) miscalculates `memmove` size (`+ consume` instead of `- consume`), causing a 2,024-byte overflow into an adjacent `exec_map` entry. Exploit preseeds kernel memory at offset 265,166 bytes to replace `sshd-session` environment with `LD_PRELOAD=/tmp/evil.so`. Race condition optimized via fragmented argument strings to slow `execve` calls. Challenges include avoiding `MADV_FREE` under memory pressure and a 3.1% panic risk. PoC achieves root in seconds.
Source: https://blog.calif.io/p/cve-2026-7270-how-i-get-root-on-freebsd
#Cybersecurity #ThreatIntel
O RLY CYBER
npub1sh…0kwr0
2026-05-07 19:27:57 UTC
Author Public Key
npub1shlut8mwdmfevu2nt294apayu7e0mxs5mrpfyq8v5ru4ymscg9ysx0kwr0Seen on
wss://relay.momostr.pinkPublished at
2026-05-07 19:27:57 UTCEvent JSON
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"content": "(calif.io) CVE-2026-7270: Root Privilege Escalation in FreeBSD via Kernel Memory Corruption in execve()\n\nNew critical LPE in FreeBSD: CVE-2026-7270 enables root access via a one-character error in `execve()` kernel handling. Exploit targets `sshd-session` with `LD_PRELOAD` injection through a race condition.\n\nIn brief - CVE-2026-7270 is a local privilege escalation flaw in FreeBSD (since 2013) caused by a sign error in `execve()` memory handling. Attackers can corrupt kernel memory during shebang script execution, inject `LD_PRELOAD`, and gain root via `sshd-session`. Affects default installations.\n\nTechnically - The bug in `sys/kern/kern_exec.c` (`exec_args_adjust_args`) miscalculates `memmove` size (`+ consume` instead of `- consume`), causing a 2,024-byte overflow into an adjacent `exec_map` entry. Exploit preseeds kernel memory at offset 265,166 bytes to replace `sshd-session` environment with `LD_PRELOAD=/tmp/evil.so`. Race condition optimized via fragmented argument strings to slow `execve` calls. Challenges include avoiding `MADV_FREE` under memory pressure and a 3.1% panic risk. PoC achieves root in seconds.\n\nSource: https://blog.calif.io/p/cve-2026-7270-how-i-get-root-on-freebsd\n\n#Cybersecurity #ThreatIntel",
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