CVE Vulnerabilities

CVE-2018-14618

Heap-based Buffer Overflow

Published: Sep 05, 2018 | Modified: Nov 21, 2024
CVSS 3.x
9.8
CRITICAL
Source:
NVD
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CVSS 2.x
10 HIGH
AV:N/AC:L/Au:N/C:C/I:C/A:C
RedHat/V2
RedHat/V3
7.5 LOW
CVSS:3.0/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H
Ubuntu
MEDIUM

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.)

Weakness

A heap overflow condition is a buffer overflow, where the buffer that can be overwritten is allocated in the heap portion of memory, generally meaning that the buffer was allocated using a routine such as malloc().

Affected Software

Name Vendor Start Version End Version
Libcurl Haxx * 7.61.1 (excluding)
Red Hat Ansible Tower 3.4 for RHEL 7 RedHat ansible-tower-34/ansible-tower-memcached:1.4.15-28 *
Red Hat Ansible Tower 3.4 for RHEL 7 RedHat ansible-tower-35/ansible-tower-memcached:1.4.15-28 *
Red Hat Ansible Tower 3.4 for RHEL 7 RedHat ansible-tower-37/ansible-tower-memcached-rhel7:1.4.15-28 *
Red Hat Enterprise Linux 7 RedHat curl-0:7.29.0-51.el7_6.3 *
Red Hat Software Collections for Red Hat Enterprise Linux 6 RedHat httpd24-curl-0:7.61.1-1.el6 *
Red Hat Software Collections for Red Hat Enterprise Linux 6 RedHat httpd24-httpd-0:2.4.34-7.el6 *
Red Hat Software Collections for Red Hat Enterprise Linux 6 RedHat httpd24-nghttp2-0:1.7.1-7.el6 *
Red Hat Software Collections for Red Hat Enterprise Linux 7 RedHat httpd24-curl-0:7.61.1-1.el7 *
Red Hat Software Collections for Red Hat Enterprise Linux 7 RedHat httpd24-httpd-0:2.4.34-7.el7 *
Red Hat Software Collections for Red Hat Enterprise Linux 7 RedHat httpd24-nghttp2-0:1.7.1-7.el7 *
Red Hat Software Collections for Red Hat Enterprise Linux 7.4 EUS RedHat httpd24-curl-0:7.61.1-1.el7 *
Red Hat Software Collections for Red Hat Enterprise Linux 7.4 EUS RedHat httpd24-httpd-0:2.4.34-7.el7 *
Red Hat Software Collections for Red Hat Enterprise Linux 7.4 EUS RedHat httpd24-nghttp2-0:1.7.1-7.el7 *
Red Hat Software Collections for Red Hat Enterprise Linux 7.5 EUS RedHat httpd24-curl-0:7.61.1-1.el7 *
Red Hat Software Collections for Red Hat Enterprise Linux 7.5 EUS RedHat httpd24-httpd-0:2.4.34-7.el7 *
Red Hat Software Collections for Red Hat Enterprise Linux 7.5 EUS RedHat httpd24-nghttp2-0:1.7.1-7.el7 *
Red Hat Software Collections for Red Hat Enterprise Linux 7.6 EUS RedHat httpd24-curl-0:7.61.1-1.el7 *
Red Hat Software Collections for Red Hat Enterprise Linux 7.6 EUS RedHat httpd24-httpd-0:2.4.34-7.el7 *
Red Hat Software Collections for Red Hat Enterprise Linux 7.6 EUS RedHat httpd24-nghttp2-0:1.7.1-7.el7 *
Curl Ubuntu bionic *
Curl Ubuntu devel *
Curl Ubuntu trusty *
Curl Ubuntu xenial *

Potential Mitigations

  • Use automatic buffer overflow detection mechanisms that are offered by certain compilers or compiler extensions. Examples include: the Microsoft Visual Studio /GS flag, Fedora/Red Hat FORTIFY_SOURCE GCC flag, StackGuard, and ProPolice, which provide various mechanisms including canary-based detection and range/index checking.
  • D3-SFCV (Stack Frame Canary Validation) from D3FEND [REF-1334] discusses canary-based detection in detail.
  • Run or compile the software using features or extensions that randomly arrange the positions of a program’s executable and libraries in memory. Because this makes the addresses unpredictable, it can prevent an attacker from reliably jumping to exploitable code.
  • Examples include Address Space Layout Randomization (ASLR) [REF-58] [REF-60] and Position-Independent Executables (PIE) [REF-64]. Imported modules may be similarly realigned if their default memory addresses conflict with other modules, in a process known as “rebasing” (for Windows) and “prelinking” (for Linux) [REF-1332] using randomly generated addresses. ASLR for libraries cannot be used in conjunction with prelink since it would require relocating the libraries at run-time, defeating the whole purpose of prelinking.
  • For more information on these techniques see D3-SAOR (Segment Address Offset Randomization) from D3FEND [REF-1335].

References