Huawei EulerOS: Security Advisory for curl (EulerOS-SA-2021-2769)

Published: 2021-11-17 03:46:51
CVE Author: NIST National Vulnerability Database

CVSS Base Vector:



severity_date=2021-08-16 15:56:00 +0000 (Mon, 16 Aug 2021)

The remote host is missing an update for the Huawei EulerOS 'curl' Linux Distribution Package(s) announced via the EulerOS-SA-2021-2769 advisory.

Detection Method:
Checks if a vulnerable Linux Distribution Package version is present on the target host.

Technical Details:
libcurl-using applications can ask for a specific client certificate to be used in a transfer. This is done with the `CURLOPT_SSLCERT` option (`--cert` with the command line tool).When libcurl is built to use the macOS native TLS library Secure Transport, an application can ask for the client certificate by name or with a file name - using the same option. If the name exists as a file, it will be used instead of by name.If the application runs with a current working directory that is writable by other users (like `/tmp`), a malicious user can create a file name with the same name as the app wants to use by name, and thereby trick the application to use the file based cert instead of the one referred to by name making libcurl send the wrong client certificate in the TLS connection handshake.(CVE-2021-22926) curl supports the `-t` command line option, known as `CURLOPT_TELNETOPTIONS`in 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.(CVE-2021-22925) libcurl keeps previously used connections in a connection pool for subsequenttransfers to reuse, if one of them matches the setup.Due to errors in the logic, the config matching function did not take 'issuercert' into account and it compared the involved paths *case insensitively*,which could lead to libcurl reusing wrong connections.File paths are, or can be, case sensitive on many systems but not all, and caneven vary depending on used file systems.The comparison also didn't include the 'issuer cert' which a transfer can setto qualify how to verify the server certificate.(CVE-2021-22924) When curl is instructed to get content using the metalink feature, and a user name and password are used to download the metalink XML file, those same credentials are then subsequently passed on to each of the servers from which curl will download or try to download the contents from. Often contrary to the user's expectations and intentions and without telling the user it happened.(CVE-2021-22923) When curl is instructed to download content using the metalink feature, thecontents is verified against a hash provided in the metalink XML file.The metalink XML file points out to the client how to get the same contentfrom a set of different URLs, potentially hosted by different servers and theclient can then download the file from one or several of them. In a serial orparallel manner.If one of the servers hosting the contents has been breached and the contentsof the specific file on that server is replaced with a ... [Please see the references for more information on the vulnerabilities]

Affected Versions:
'curl' Linux Distribution Package(s) on Huawei EulerOS Virtualization release 2.9.0.

Please install the updated Linux Distribution Package(s).

Solution Type:
Vendor Patch

Detection Type:
Linux Distribution Package

NIST (National Institute of Standards and Technology) NVD (National Vulnerability Database)


CVSS Score
Huawei EulerOS Local Security Checks

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