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Bug #13069

closed

Input validation for IPv6 addresses allows invalid address compression in some cases

Added by Marcos M over 2 years ago. Updated over 2 years ago.

Status:
Resolved
Priority:
Normal
Assignee:
Category:
Web Interface
Target version:
Start date:
Due date:
% Done:

100%

Estimated time:
Plus Target Version:
22.05
Release Notes:
Default
Affected Version:
Affected Architecture:

Description

Tested on 22.05.a.20220412.0600.

There is no input validation for IPv6 addresses with multiple instances of the characters :: e.g. fc00::5::1. This prevents the firewall from booting, causes PHP crashes, and prevents the ruleset from being loaded correctly.

Actions #1

Updated by Viktor Gurov over 2 years ago

  • Status changed from New to Feedback
  • Priority changed from High to Normal

unable to reproduce - is_ipaddrv6('fc00::5::1') returns false

Actions #2

Updated by Jim Pingle over 2 years ago

Same here, validation works fine in places I've tried it (e.g. alias content)

We will need a list of specific pages and settings which can trigger the failures. It's possible some fields lack full validation but it's definitely not lacking everywhere.

Actions #3

Updated by Jim Pingle over 2 years ago

  • Status changed from Feedback to Confirmed

Marcos sent me a different IPv6 string directly and that does validate when it should not, which I then used to check a few different ways and found there is a problem.

Net_IPv6::checkIPv6($ipaddr) checks the number of parts in the address and it validates if there are 8 parts, even if they are compressed with :: more than once, which is invalid. It's arguably unambiguous, because there are still exactly 8 parts, but it's still not valid.

var_dump(is_ipaddrv6('1:2:3:4::6::8'));
var_dump(is_ipaddrv6('1:2:3::5:6::8'));
var_dump(is_ipaddrv6('1:2::4:5:6::8'));
var_dump(is_ipaddrv6('1::3:4:5:6::8'));
var_dump(is_ipaddrv6('1:2::4::6::8'));
var_dump(is_ipaddrv6('1::3:4::6::8'));
var_dump(is_ipaddrv6('1::3::5:6::8'));
var_dump(is_ipaddrv6('1::3::5::7:8'));
bool(true)
bool(true)
bool(true)
bool(true)
bool(true)
bool(true)
bool(true)
bool(true)

It should outright reject anything with more than one occurrence of :: in the address.

Actions #4

Updated by Jim Pingle over 2 years ago

  • Status changed from Confirmed to In Progress
  • Assignee set to Jim Pingle
  • Target version set to 2.7.0
  • Plus Target Version set to 22.05
Actions #5

Updated by Jim Pingle over 2 years ago

  • Status changed from In Progress to Pull Request Review

MR: https://gitlab.netgate.com/pfSense/pfSense/-/merge_requests/724

With the change in the MR, the results are as expected. Valid uses of single compression are OK, multiple are rejected.

var_dump(is_ipaddrv6('1:2:3:4:5:6:7:8'));
var_dump(is_ipaddrv6('1:2:3:4:5:6::8'));
var_dump(is_ipaddrv6('1:2:3:4::8'));
var_dump(is_ipaddrv6('1:2:3::5:6::8'));
var_dump(is_ipaddrv6('1:2::4:5:6::8'));
var_dump(is_ipaddrv6('1::3:4:5:6::8'));
var_dump(is_ipaddrv6('1:2::4::6::8'));
var_dump(is_ipaddrv6('1::3:4::6::8'));
var_dump(is_ipaddrv6('1::3::5:6::8'));
var_dump(is_ipaddrv6('1::3::5::7:8'));
bool(true)
bool(true)
bool(true)
bool(false)
bool(false)
bool(false)
bool(false)
bool(false)
bool(false)
bool(false)
Actions #6

Updated by Marcos M over 2 years ago

Tested with the IP that broke it previously in different places e.g. alias, interface, vip, freeradius. All worked (rejected with multiple instances of :: and accepted with the valid IP). Thanks!

Actions #7

Updated by Jim Pingle over 2 years ago

  • Status changed from Pull Request Review to Feedback
  • % Done changed from 0 to 100
Actions #8

Updated by Marcos M over 2 years ago

  • Status changed from Feedback to Resolved
Actions #9

Updated by Jim Pingle over 2 years ago

  • Subject changed from Improve interface input validation for IPv6 to Input validation for IPv6 addresses allows invalid address compression in some cases

Updating subject for release notes.

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