Local privilege escalation via incorrect eBPF bounds
Published Apr 2, 2020 · Updated Sep 17, 2024
Out-of-bounds access in Linux Kernel 5.4.7 through 5.4.28, 5.5.0 through 5.5.13, and 5.6 allows local users to gain root privileges. The eBPF verifier's 32-bit jump-bound update derives a narrow tracked-number range from only a register's minimum and maximum values, so crafted code can make it accept out-of-bounds map-pointer arithmetic. Exploitation requires the ability to load unprivileged eBPF programs; the resulting primitive permits arbitrary kernel-memory reads and writes.
Summary
What happened
Out-of-bounds access in Linux Kernel 5.4.7 through 5.4.28, 5.5.0 through 5.5.13, and 5.6 allows local users to gain root privileges. The eBPF verifier's 32-bit jump-bound update derives a narrow tracked-number range from only a register's minimum and maximum values, so crafted code can make it accept out-of-bounds map-pointer arithmetic. Exploitation requires the ability to load unprivileged eBPF programs; the resulting primitive permits arbitrary kernel-memory reads and writes.
The record
- CVE
- CVE-2020-8835
- Published
- Apr 2, 2020
- Updated
- Sep 17, 2024
- Vendor
- The Linux Kernel Organization
- Product
- Linux Kernel
- Classifications
- CWE-787, CWE-125, T1068
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Apr 2, 2020CVE publishedPublication date reported by the CVE source.
- Sep 17, 2024Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
Compare your product and version with the public record. A matching version still requires validation against your environment.
Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=5.4.7 <5.4-stable* changes=[{"at":"5.4.29","status":"unaffected"}]
- Affected versionversion=5.5-stable <5.5.14
- Affected versionversion=5.6-stable <5.6.1
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- Pwn2Own eBPF privilege-escalation demonstrationfunctional · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Reported exploitation
- Pwn2Own 2020 contest exploitationreported exploitation
Technologies
Your stack
See the directory against your own environment.
Your stack
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