CVE-2021-22922

2021-07-2100:00:00

ubuntu.com

6.5 Medium

CVSS3

Attack Vector

NETWORK

Attack Complexity

LOW

Privileges Required

NONE

User Interaction

REQUIRED

Scope

UNCHANGED

Confidentiality Impact

NONE

Integrity Impact

HIGH

Availability Impact

NONE

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N

4.3 Medium

CVSS2

Access Vector

NETWORK

Access Complexity

MEDIUM

Authentication

NONE

Confidentiality Impact

NONE

Integrity Impact

PARTIAL

Availability Impact

NONE

AV:N/AC:M/Au:N/C:N/I:P/A:N

0.004 Low

EPSS

Percentile

71.6%

JSON

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 modified payload, curlshould detect this when the
hash of the file mismatches after a completeddownload. It should remove the
contents and instead try getting the contentsfrom another URL. This is not
done, and instead such a hash mismatch is onlymentioned in text and the
potentially malicious content is kept in the file ondisk.

Notes

Author	Note
mdeslaur	introduced in 7.27.0 per upstream “curl has completely removed the metalink feature as of 7.78.0. No fix for this flaw will be produced by the curl project. The fix for earlier versions is to rebuild curl with the metalink support switched off!” Ubuntu builds curl with metalink support switched off already.