SB2021010812 - GitLab security update for bundler and curl



SB2021010812 - GitLab security update for bundler and curl

Published: January 8, 2021 Updated: October 28, 2023

Security Bulletin ID SB2021010812
Severity
Medium
Patch available
YES
Number of vulnerabilities 4
Exploitation vector Remote access
Highest impact Code execution

Breakdown by Severity

Medium 50% Low 50%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 4 secuirty vulnerabilities.


1) Files or Directories Accessible to External Parties (CVE-ID: CVE-2019-3881)

The vulnerability allows a local user to escalate privileges on the system.

The vulnerability exists due to Bundler uses a predictable path in /tmp/, created with insecure permissions as a storage location for gems, if locations under the user's home directory are not available. If Bundler is used in a scenario where the user does not have a writable home directory, an attacker could place malicious code in this directory that would be later loaded and executed.


2) Improper Check for Certificate Revocation (CVE-ID: CVE-2020-8286)

The vulnerability allows a remote attacker to bypass implemented security restrictions.

The vulnerability exists due to incorrectly implemented checks for OCSP stapling. A remote attacker can provide a fraudulent OCSP response that would appear fine, instead of the real one.


3) Uncontrolled Recursion (CVE-ID: CVE-2020-8285)

The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due tu uncontrolled recursion when processing FTP responses within the wildcard matching functionality, which allows a callback (set with <a href="https://curl.se/libcurl/c/CURLOPT_CHUNK_BGN_FUNCTION.html">CURLOPT_CHUNK_BGN_FUNCTION</a>) to return information back to libcurl on how to handle a specific entry in a directory when libcurl iterates over a list of all available entries. A remote attacker who controls the malicious FTP server can trick the victim to connect to it and crash the application, which is using the affected libcurl version.


4) Information disclosure (CVE-ID: CVE-2020-8284)

The vulnerability allows a remote attacker to gain access to potentially sensitive information.

The vulnerability exists due to the way cURL handles PASV responses. A remote attacker with control over malicious FTP server can use the PASV response to trick curl into connecting back to a given IP address and port, and this way potentially make curl extract information about services that are otherwise private and not disclosed, for example doing port scanning and service banner extractions.


Remediation

Install update from vendor's website.