CVE-2017-1000257

curl: IMAP FETCH response out of bounds read

Published Oct 31, 2017 CVSS 3.1 · 9.1 Critical EPSS 6.2% KEV · Not listed
Description
An IMAP FETCH response line indicates the size of the returned data, in number of bytes. When that response says the data is zero bytes, libcurl would pass on that (non-existing) data with a pointer and the size (zero) to the deliver-data function. libcurl's deliver-data function treats zero as a magic number and invokes strlen() on the data to figure out the length. The strlen() is called on a heap based buffer that might not be zero terminated so libcurl might read beyond the end of it into whatever memory lies after (or just crash) and then deliver that to the application as if it was actually downloaded.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Debian DLA Debian DLA DLA-1143-1 curl security update
Debian DSA Debian DSA DSA-4007-1 curl security update
EUVD EUVD EUVD-2017-1518 An IMAP FETCH response line indicates the size of the returned data, in number of bytes. When that response says the data is zero bytes, libcurl would pass on that (non-existing) data with a pointer and the size (zero) to the deliver-data function. libcurl's deliver-data function treats zero as a magic number and invokes strlen() on the data to figure out the length. The strlen() is called on a heap based buffer that might not be zero terminated so libcurl might read beyond the end of it into whatever memory lies after (or just crash) and then deliver that to the application as if it was actually downloaded.
Ubuntu USN Ubuntu USN USN-3441-2 curl vulnerabilities
Ubuntu USN Ubuntu USN USN-3457-1 curl vulnerability
History
Type Values Removed Values Added
Metrics cvssV3_1

{'score': 9.1, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H'}

ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
mitre
Published
Updated
Apr 15, 2026, 9:02 PM
Reserved
Oct 31, 2017, 12:00 AM
Status
Modified
Published
Oct 31, 2017, 9:29 PM
Modified
Jun 17, 2026, 12:59 AM
Severity
Moderate
Public date
Oct 23, 2017, 12:00 AM