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Security #4504

closed

tcp: Evasion possibility on wrong/unexpected ACK value in crafted SYN packets

Added by Peter Manev over 1 year ago. Updated 12 months ago.

Status:
Closed
Priority:
Normal
Assignee:
Target version:
Affected Versions:
Label:
Needs backport to 5.0, Needs backport to 6.0
Git IDs:

0d81173d6e912f4be9e3e8f7593d779d8ffed52f
556570f7dd7f21f11cffda5ebcb72738a29cbb90
2c8c043185a4700b042d2154f5076f1c82e5394b

Severity:
CRITICAL

Description

affected versions: all

Please see the pcap attached.
Basically it logs no HTTP even with midstream enabled.

The problem is the first packet right away as it has ACK value that we check and disregard the whole flow/session.But Windows and Linux accept those and everyone else it seems.

Please also see attached a test case(py file) and a patch by Eric.

The pcap can not be shared or made public except of the devs with access to this issue of course.


Files


Related issues 2 (0 open2 closed)

Copied to Security #4512: Evasion possibility on wrong/unexpected ACK value in crafted SYN packetsClosedVictor JulienActions
Copied to Security #4513: Evasion possibility on wrong/unexpected ACK value in crafted SYN packetsClosedJeff LucovskyActions
Actions #1

Updated by Victor Julien over 1 year ago

  • Tracker changed from Bug to Security
  • Priority changed from Normal to High
Actions #2

Updated by Victor Julien over 1 year ago

  • Label Needs backport to 5.0, Needs backport to 6.0 added
Actions #3

Updated by Victor Julien over 1 year ago

  • File deleted (small-eth1-TLPRED.pcap)
Actions #4

Updated by Jeff Lucovsky over 1 year ago

  • Copied to Security #4512: Evasion possibility on wrong/unexpected ACK value in crafted SYN packets added
Actions #5

Updated by Jeff Lucovsky over 1 year ago

  • Copied to Security #4513: Evasion possibility on wrong/unexpected ACK value in crafted SYN packets added
Actions #6

Updated by Victor Julien over 1 year ago

  • Status changed from New to In Progress
  • Assignee set to Eric Leblond
  • Target version set to 7.0.0-beta1
  • CVE set to 2021-35063
Actions #7

Updated by Victor Julien over 1 year ago

  • Severity set to CRITICAL
Actions #8

Updated by Victor Julien over 1 year ago

  • Status changed from In Progress to Closed
  • Priority changed from High to Normal
  • Git IDs updated (diff)
Actions #9

Updated by Victor Julien about 1 year ago

  • Subject changed from Evasion possibility on wrong/unexpected ACK value in crafted SYN packets to tcp: Evasion possibility on wrong/unexpected ACK value in crafted SYN packets
Actions #10

Updated by Victor Julien 12 months ago

  • Private changed from Yes to No
Actions

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