curl supports "globbing" of URLs, in which a user can pass a numerical range to have the tool iterate over those numbers to do a sequence of transfers. In the globbing function that parses the numerical range, there was an omission that made curl read a byte beyond the end of the URL if given a carefully crafted, or just wrongly written, URL. The URL is stored in a heap based buffer, so it could then be made to wrongly read something else instead of crashing. An example of a URL that triggers the flaw would be `http://ur%20[0-60000000000000000000`.
http://www.debian.org/security/2017/dsa-3992
http://www.securityfocus.com/bid/100249
http://www.securitytracker.com/id/1039117
https://access.redhat.com/errata/RHSA-2018:3558
https://curl.haxx.se/docs/adv_20170809A.html
Source: MITRE
Published: 2017-10-05
Updated: 2018-11-13
Type: CWE-119
Base Score: 4.3
Vector: AV:N/AC:M/Au:N/C:P/I:N/A:N
Impact Score: 2.9
Exploitability Score: 8.6
Severity: MEDIUM
Base Score: 6.5
Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N
Impact Score: 3.6
Exploitability Score: 2.8
Severity: MEDIUM