Bug 1575533 (CVE-2018-1000300) - CVE-2018-1000300 curl: FTP shutdown response heap-based buffer overflow can potentially lead to RCE
Summary: CVE-2018-1000300 curl: FTP shutdown response heap-based buffer overflow can p...
Alias: CVE-2018-1000300
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
Target Milestone: ---
Assignee: Red Hat Product Security
QA Contact:
Depends On: 1578682 1578683 1578684
Blocks: 1575537
TreeView+ depends on / blocked
Reported: 2018-05-07 08:26 UTC by Adam Mariš
Modified: 2021-09-09 13:58 UTC (History)
25 users (show)

Fixed In Version: curl 7.60.0
Doc Type: If docs needed, set a value
Doc Text:
Clone Of:
Last Closed: 2018-05-10 22:05:43 UTC

Attachments (Terms of Use)
Upstream patch (1.46 KB, patch)
2018-05-07 08:46 UTC, Adam Mariš
no flags Details | Diff

Description Adam Mariš 2018-05-07 08:26:35 UTC
A heap-based buffer overflow can happen when closing down an FTP connection with very long server command replies.

When doing FTP transfers, curl keeps a spare "closure handle" around internally that will be used when an FTP connection gets shut down since the original curl easy handle is then already removed.

FTP server response data that gets cached from the original transfer might then be larger than the default buffer size (16 KB) allocated in the "closure handle", which can lead to a buffer overwrite. The contents and size of that overwrite is controllable by the server.

This situation was detected by an assert() in the code, but that was of course only preventing bad stuff in debug builds. This bug is very unlikely to trigger with non-malicious servers.

This issue was introduced by:


Affected versions: curl 7.54.1 to and including curl 7.59.0
Not affected versions: curl < 7.54.1 and curl >= 7.60.0

Comment 1 Adam Mariš 2018-05-07 08:26:38 UTC

Name: the Curl project
Upstream: Dario Weisser

Comment 2 Adam Mariš 2018-05-07 08:46:54 UTC
Created attachment 1432531 [details]
Upstream patch

Comment 3 Adam Mariš 2018-05-16 07:25:38 UTC
External References:


Comment 4 Adam Mariš 2018-05-16 07:27:10 UTC
Created curl tracking bugs for this issue:

Affects: fedora-all [bug 1578683]

Created mingw-curl tracking bugs for this issue:

Affects: fedora-all [bug 1578684]

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