Impact: Moderate Public Date: 2019-02-06 CWE: CWE-125 Bugzilla: 1670252: CVE-2018-16890 curl: NTLM type-2 heap out-of-bounds buffer read libcurl versions from 7.36.0 to before 7.64.0 is vulnerable to a heap buffer out-of-bounds read. The function handling incoming NTLM type-2 messages (`lib/vauth/ntlm.c:ntlm_decode_type2_target`) does not validate incoming data correctly and is subject to an integer overflow vulnerability. Using that overflow, a malicious or broken NTLM server could trick libcurl to accept a bad length + offset combination that would lead to a buffer read out-of-bounds.
The MITRE CVE dictionary describes this issue as:
Find out more about CVE-2018-16890 from the MITRE CVE dictionary dictionary and NIST NVD.
The versions of curl package shipped with Red Hat Enterprise Linux 5, 6 and 7 do not support NTLMv2 type-2 headers, hence they are not affected by this flaw.
NOTE: The following CVSS v3 metrics and score provided are preliminary and subject to review.
| CVSS3 Base Score | 4.3 |
|---|---|
| CVSS3 Base Metrics | CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L |
| Attack Vector | Network |
| Attack Complexity | Low |
| Privileges Required | None |
| User Interaction | Required |
| Scope | Unchanged |
| Confidentiality | None |
| Integrity Impact | None |
| Availability Impact | Low |
| Platform | Package | State |
|---|---|---|
| Red Hat Virtualization 4 | curl | Under investigation |
| Red Hat Software Collections for Red Hat Enterprise Linux | httpd24-curl | Affected |
| Red Hat JBoss Web Server 5 | curl | Under investigation |
| Red Hat JBoss Core Services 1 | curl | Under investigation |
| Red Hat Enterprise Linux 7 | curl | Not affected |
| Red Hat Enterprise Linux 6 | curl | Not affected |
| Red Hat Enterprise Linux 5 | curl | Not affected |
| .NET Core 2.0 on Red Hat Enterprise Linux | rh-dotnet22-curl | Under investigation |
| .NET Core 2.0 on Red Hat Enterprise Linux | rh-dotnet21-curl | Under investigation |
| .NET Core 1.0 on Red Hat Enterprise Linux | rh-dotnetcore10-curl | Under investigation |
| .NET Core 1.0 on Red Hat Enterprise Linux | rh-dotnetcore11-curl | Under investigation |
Turn off NTLM authentication.
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