LINUX_ exposes major bash security vulnerabilities and remediation methods

Source: Internet
Author: User
Tags function definition cve aliyun

Linux official built-in bash recently found a very serious security Vulnerability (vulnerability reference, Hackers can take advantage of this bash vulnerability to fully control the target system and initiate an attack.

Software and systems that have been successfully exploited: All Linux operating systems installed with GNU Bash version less than or equal to 4.3. The vulnerability stems from the special environment variables created before the bash shell that you invoke, which can contain code and be executed by bash.

Vulnerability detection methods:

1 envx=‘() { :;}; echo vulnerable‘ bash-c "echo this is a test"


Before repair
This is a test
After repairing with the patching scheme
BASH:WARNING:X: Ignoring function definition attempt
Bash:error importing function definition for ' x '
This is a test

Special NOTE: This fix will not have any effect, if your script uses the above method to define environment variables, your script execution will error when repaired.

Fix solution:

14.04 64bit

123 wget && dpkg -i bash_4.3-7ubuntu1.1_amd64.deb

14.04 32bit

123 wget && dpkg -i  bash_4.3-7ubuntu1.1_i386.deb

12.04 64bit

123 wget && dpkg -i  bash_4.2-2ubuntu2.2_amd64.deb

12.04 32bit

123 wget && dpkg -i  bash_4.2-2ubuntu2.2_i386.deb

Ubuntu users can patch with the following commands without restarting:

123 apt-get update   apt-get installbash

Reference links and other Linux system repair scenarios: Linux bash critical bug fix emergency notification

Reprint: Original source

LINUX_ exposes major bash security vulnerabilities and remediation methods

Contact Us

The content source of this page is from Internet, which doesn't represent Alibaba Cloud's opinion; products and services mentioned on that page don't have any relationship with Alibaba Cloud. If the content of the page makes you feel confusing, please write us an email, we will handle the problem within 5 days after receiving your email.

If you find any instances of plagiarism from the community, please send an email to: and provide relevant evidence. A staff member will contact you within 5 working days.

A Free Trial That Lets You Build Big!

Start building with 50+ products and up to 12 months usage for Elastic Compute Service

  • Sales Support

    1 on 1 presale consultation

  • After-Sales Support

    24/7 Technical Support 6 Free Tickets per Quarter Faster Response

  • Alibaba Cloud offers highly flexible support services tailored to meet your exact needs.