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curl / Docs / curl CVEs / URL globbing out of bounds read


URL globbing out of bounds read

Project curl Security Advisory, August 9th 2017 - Permalink


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.


This flaw only affects the curl command line tool, not the libcurl library.

For version 7.55.0, the parser properly stops at the end of the string and a test has been added to verify this.

The Common Vulnerabilities and Exposures (CVE) project has assigned the name CVE-2017-1000101 to this issue.

CWE-126: Buffer Over-read

Severity: Medium


curl is used by many applications, but not always advertised as such.



We suggest you take one of the following actions immediately, in order of preference:

A - Upgrade curl to version 7.55.0

B - Apply the patch to your version and rebuild


It was reported to the curl project on June 14, 2017. We contacted distros@openwall on August 1.

curl 7.55.0 was released on August 9 2017, coordinated with the publication of this advisory.


Thanks a lot!