CVE-2018-14618

curl: NTLM password overflow via integer overflow

Published Sep 5, 2018 CVSS 3.0 · 7.5 High EPSS 10.7% KEV · Not listed
Description
curl before version 7.61.1 is vulnerable to a buffer overrun in the NTLM authentication code. The internal function Curl_ntlm_core_mk_nt_hash multiplies the length of the password by two (SUM) to figure out how large temporary storage area to allocate from the heap. The length value is then subsequently used to iterate over the password and generate output into the allocated storage buffer. On systems with a 32 bit size_t, the math to calculate SUM triggers an integer overflow when the password length exceeds 2GB (2^31 bytes). This integer overflow usually causes a very small buffer to actually get allocated instead of the intended very huge one, making the use of that buffer end up in a heap buffer overflow. (This bug is almost identical to CVE-2017-8816.)

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Debian DLA Debian DLA DLA-1498-1 curl security update
Debian DSA Debian DSA DSA-4286-1 curl security update
EUVD EUVD EUVD-2018-6525 curl before version 7.61.1 is vulnerable to a buffer overrun in the NTLM authentication code. The internal function Curl_ntlm_core_mk_nt_hash multiplies the length of the password by two (SUM) to figure out how large temporary storage area to allocate from the heap. The length value is then subsequently used to iterate over the password and generate output into the allocated storage buffer. On systems with a 32 bit size_t, the math to calculate SUM triggers an integer overflow when the password length exceeds 2GB (2^31 bytes). This integer overflow usually causes a very small buffer to actually get allocated instead of the intended very huge one, making the use of that buffer end up in a heap buffer overflow. (This bug is almost identical to CVE-2017-8816.)
Ubuntu USN Ubuntu USN USN-3765-1 curl vulnerability
Ubuntu USN Ubuntu USN USN-3765-2 curl vulnerability
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
redhat
Published
Updated
Apr 15, 2026, 8:54 PM
Reserved
Jul 27, 2018, 12:00 AM
Status
Modified
Published
Sep 5, 2018, 7:29 PM
Modified
Jun 17, 2026, 1:41 AM
Severity
Low
Public date
Sep 5, 2018, 12:00 AM