ROS-2-441

2.441 Vulnerability in Curl (CVE-2020-8177)

1. Vulnerability Description:

The vulnerability allows a local file on the system to be overwritten when accessing an attacker-controlled server. The problem only occurs when the “-J” (“–remote-header-name”) and “-i” (“–head”) options are used simultaneously. The “-J” option allows saving a file with the name specified in the “Content-Disposition” header. If a file with this name already exists, curl program in normal mode refuses to overwrite it, but in case of “-i” option the logic of checking is broken and the file is overwritten (checking is performed at the stage of receiving the response body, but with “-i” option HTTP headers are output first and they have time to be saved before the start of processing the response body). Only HTTP headers are written to the file, but the server can give arbitrary data instead of headers and they will be written.Identifier of the Information Security Threats Data Bank of the FSTEC of Russia: BDU:2020-03241

2. Possible measures to eliminate the vulnerability

It is necessary to prohibit the use of the curl utility. or - install security updates for the package: curl-7.61.1Installing updates is possible in the following ways:**a) if the computer with the installed OS version has access to the vendor’s official repository, run the update as administrator with the command:# yum updateAfter the list of updated packages is displayed, agree to apply the updates by pressing theY**key on the keyboard. Wait until the updates installation is complete and make sure that there are no errors during their installation.b)If the computer with the installed OS version does not have access to the vendor’s official repository, you should perform the following actions: - download the updated package (and dependencies if necessary): http://repo.red-soft.ru/redos/7.2c/x86_64/updates/curl-7.61.1-14.el7.x86_64.rpm Check the package integrity and authenticity by instructionsInstall the downloaded package with the command:# yum localinstall curl-7.61.1-14.el7.x86_64.rpmWhen the list of updated packages is displayed, agree to apply the updates by pressingY on the keyboard. Wait for the updates to finish installing and make sure there are no errors during installation.

Date of last modification: 08.09.2021