Vulnerabilities > CVE-2021-20268 - Integer Overflow or Wraparound vulnerability in Linux Kernel
Attack vector
LOCAL Attack complexity
LOW Privileges required
LOW Confidentiality impact
HIGH Integrity impact
HIGH Availability impact
HIGH Summary
An out-of-bounds access flaw was found in the Linux kernel's implementation of the eBPF code verifier in the way a user running the eBPF script calls dev_map_init_map or sock_map_alloc. This flaw allows a local user to crash the system or possibly escalate their privileges. The highest threat from this vulnerability is to confidentiality, integrity, as well as system availability.
Vulnerable Configurations
Common Weakness Enumeration (CWE)
Common Attack Pattern Enumeration and Classification (CAPEC)
- Forced Integer Overflow This attack forces an integer variable to go out of range. The integer variable is often used as an offset such as size of memory allocation or similarly. The attacker would typically control the value of such variable and try to get it out of range. For instance the integer in question is incremented past the maximum possible value, it may wrap to become a very small, or negative number, therefore providing a very incorrect value which can lead to unexpected behavior. At worst the attacker can execute arbitrary code.
References
- https://bugzilla.redhat.com/show_bug.cgi?id=1923816
- https://bugzilla.redhat.com/show_bug.cgi?id=1923816
- https://lore.kernel.org/bpf/CACAyw99bEYWJCSGqfLiJ9Jp5YE1ZsZSiJxb4RFUTwbofipf0dA%40mail.gmail.com/T/#m8929643e99bea9c18ed490a7bc2591145eac6444
- https://lore.kernel.org/bpf/CACAyw99bEYWJCSGqfLiJ9Jp5YE1ZsZSiJxb4RFUTwbofipf0dA%40mail.gmail.com/T/#m8929643e99bea9c18ed490a7bc2591145eac6444
- https://security.netapp.com/advisory/ntap-20210409-0006/
- https://security.netapp.com/advisory/ntap-20210409-0006/