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[ CVE-2017-1000253 · Published 5 Oct 2017 ]

Linux Kernel PIE Stack Buffer Corruption Vulnerability

Exploited · CISA KEV CVSS 7.8 EPSS 11%Fix available

[ Why it matters ]Priority signals

  • Exploited in the wild: on CISA's Known Exploited Vulnerabilities list since 2024-09-09
  • Known to be used in ransomware campaigns
  • EPSS: 11% chance of exploitation in the next 30 days (higher than 96% of CVEs)

[ Description ]Official description

Linux distributions that have not patched their long-term kernels with https://git.kernel.org/linus/a87938b2e246b81b4fb713edb371a9fa3c5c3c86 (committed on April 14, 2015). This kernel vulnerability was fixed in April 2015 by commit a87938b2e246b81b4fb713edb371a9fa3c5c3c86 (backported to Linux 3.10.77 in May 2015), but it was not recognized as a security threat. With CONFIG_ARCH_BINFMT_ELF_RANDOMIZE_PIE enabled, and a normal top-down address allocation strategy, load_elf_binary() will attempt to map a PIE binary into an address range immediately below mm->mmap_base. Unfortunately, load_elf_ binary() does not take account of the need to allocate sufficient space for the entire binary which means that, while the first PT_LOAD segment is mapped below mm->mmap_base, the subsequent PT_LOAD segment(s) end up being mapped above mm->mmap_base into the are that is supposed to be the "gap" between the stack and the binary.

CISA: Linux kernel contains a position-independent executable (PIE) stack buffer corruption vulnerability in load_elf_ binary() that allows a local attacker to escalate privileges.

[ Fixes ]Fixes and patches

CISA required action (US federal deadline 30 Sep 2024): Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.

[ References ]References