Vulnerabilities > CVE-2021-47109 - Integer Overflow or Wraparound vulnerability in Linux Kernel
Attack vector
LOCAL Attack complexity
LOW Privileges required
LOW Confidentiality impact
NONE Integrity impact
NONE Availability impact
HIGH Summary
In the Linux kernel, the following vulnerability has been resolved: neighbour: allow NUD_NOARP entries to be forced GCed IFF_POINTOPOINT interfaces use NUD_NOARP entries for IPv6. It's possible to fill up the neighbour table with enough entries that it will overflow for valid connections after that. This behaviour is more prevalent after commit 58956317c8de ("neighbor: Improve garbage collection") is applied, as it prevents removal from entries that are not NUD_FAILED, unless they are more than 5s old.
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://git.kernel.org/stable/c/7a6b1ab7475fd6478eeaf5c9d1163e7a18125c8f
- https://git.kernel.org/stable/c/7a6b1ab7475fd6478eeaf5c9d1163e7a18125c8f
- https://git.kernel.org/stable/c/d17d47da59f726dc4c87caebda3a50333d7e2fd3
- https://git.kernel.org/stable/c/d17d47da59f726dc4c87caebda3a50333d7e2fd3
- https://git.kernel.org/stable/c/d99029e6aab62aef0a0251588b2867e77e83b137
- https://git.kernel.org/stable/c/d99029e6aab62aef0a0251588b2867e77e83b137
- https://git.kernel.org/stable/c/ddf088d7aaaaacfc836104f2e632b29b1d383cfc
- https://git.kernel.org/stable/c/ddf088d7aaaaacfc836104f2e632b29b1d383cfc