CVE Vulnerabilities

CVE-2021-22925

Exposure of Sensitive Information to an Unauthorized Actor

Published: Aug 05, 2021 | Modified: Nov 21, 2024
CVSS 3.x
5.3
MEDIUM
Source:
NVD
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
CVSS 2.x
5 MEDIUM
AV:N/AC:L/Au:N/C:P/I:N/A:N
RedHat/V2
RedHat/V3
3.1 LOW
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:N/A:N
Ubuntu
MEDIUM

curl supports the -t command line option, known as CURLOPT_TELNETOPTIONSin libcurl. This rarely used option is used to send variable=content pairs toTELNET servers.Due to flaw in the option parser for sending NEW_ENV variables, libcurlcould be made to pass on uninitialized data from a stack based buffer to theserver. Therefore potentially revealing sensitive internal information to theserver using a clear-text network protocol.This could happen because curl did not call and use sscanf() correctly whenparsing the string provided by the application.

Weakness

The product exposes sensitive information to an actor that is not explicitly authorized to have access to that information.

Affected Software

Name Vendor Start Version End Version
Curl Haxx 7.7 (including) 7.78.0 (excluding)
Red Hat Enterprise Linux 8 RedHat curl-0:7.61.1-22.el8 *
Curl Ubuntu bionic *
Curl Ubuntu devel *
Curl Ubuntu esm-infra/xenial *
Curl Ubuntu focal *
Curl Ubuntu groovy *
Curl Ubuntu hirsute *
Curl Ubuntu impish *
Curl Ubuntu jammy *
Curl Ubuntu kinetic *
Curl Ubuntu lunar *
Curl Ubuntu trusty *
Curl Ubuntu trusty/esm *
Curl Ubuntu upstream *
Curl Ubuntu xenial *

Extended Description

There are many different kinds of mistakes that introduce information exposures. The severity of the error can range widely, depending on the context in which the product operates, the type of sensitive information that is revealed, and the benefits it may provide to an attacker. Some kinds of sensitive information include:

Information might be sensitive to different parties, each of which may have their own expectations for whether the information should be protected. These parties include:

Information exposures can occur in different ways:

It is common practice to describe any loss of confidentiality as an “information exposure,” but this can lead to overuse of CWE-200 in CWE mapping. From the CWE perspective, loss of confidentiality is a technical impact that can arise from dozens of different weaknesses, such as insecure file permissions or out-of-bounds read. CWE-200 and its lower-level descendants are intended to cover the mistakes that occur in behaviors that explicitly manage, store, transfer, or cleanse sensitive information.

Potential Mitigations

  • Compartmentalize the system to have “safe” areas where trust boundaries can be unambiguously drawn. Do not allow sensitive data to go outside of the trust boundary and always be careful when interfacing with a compartment outside of the safe area.
  • Ensure that appropriate compartmentalization is built into the system design, and the compartmentalization allows for and reinforces privilege separation functionality. Architects and designers should rely on the principle of least privilege to decide the appropriate time to use privileges and the time to drop privileges.

References