CVE-2021-47245
netfilter: synproxy: Fix out of bounds when parsing TCP options
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Description
In the Linux kernel, the following vulnerability has been resolved: netfilter: synproxy: Fix out of bounds when parsing TCP options The TCP option parser in synproxy (synproxy_parse_options) could read one byte out of bounds. When the length is 1, the execution flow gets into the loop, reads one byte of the opcode, and if the opcode is neither TCPOPT_EOL nor TCPOPT_NOP, it reads one more byte, which exceeds the length of 1. This fix is inspired by commit 9609dad263f8 ("ipv4: tcp_input: fix stack out of bounds when parsing TCP options."). v2 changes: Added an early return when length < 0 to avoid calling skb_header_pointer with negative length.
Affected
Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.
Remediation
No guide yetNo remediation guidance has been written for this CVE yet. What the record does show:
Patch and advisory references
- https://git.kernel.org/stable/c/576c1526b4d83c44ad7b673cb841f36cbc6cb6c4
- https://git.kernel.org/stable/c/5fc177ab759418c9537433e63301096e733fb915
- https://git.kernel.org/stable/c/674b5f0c6a4fc5d3abce877048290cea6091fcb1
- https://git.kernel.org/stable/c/6defc77d48eff74075b80ad5925061b2fc010d98
- https://git.kernel.org/stable/c/7d9a9a1a88a3da574e019b4de756bc73337b3b0b
References (8)
SSVC — Action Prioritization
SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.
CVSS
- Attack Vector
- LOCAL
- Complexity
- LOW
- Privileges
- LOW
- User Interaction
- NONE
- Scope
- UNCHANGED
- Confidentiality
- HIGH
- Integrity
- NONE
- Availability
- HIGH
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