CVE Vulnerabilities

CVE-2018-1000120

Out-of-bounds Write

Published: Mar 14, 2018 | Modified: Jun 18, 2019
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
7.5 HIGH
AV:N/AC:L/Au:N/C:P/I:P/A:P
RedHat/V2
RedHat/V3
5.4 MODERATE
CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:L
Ubuntu
MEDIUM

A buffer overflow exists in curl 7.12.3 to and including curl 7.58.0 in the FTP URL handling that allows an attacker to cause a denial of service or worse.

Weakness

The product writes data past the end, or before the beginning, of the intended buffer.

Affected Software

Name Vendor Start Version End Version
Debian_linux Debian 7.0 (including) 7.0 (including)
Debian_linux Debian 8.0 (including) 8.0 (including)
Debian_linux Debian 9.0 (including) 9.0 (including)
JBoss Core Services Apache HTTP Server 2.4.29 SP2 RedHat curl *
Red Hat Enterprise Linux 7 RedHat curl-0:7.29.0-51.el7 *
Red Hat Enterprise Linux 7 RedHat nss-pem-0:1.0.3-5.el7 *
Red Hat Enterprise Linux 7.4 Advanced Update Support RedHat curl-0:7.29.0-42.el7_4.2 *
Red Hat Enterprise Linux 7.4 Telco Extended Update Support RedHat curl-0:7.29.0-42.el7_4.2 *
Red Hat Enterprise Linux 7.4 Update Services for SAP Solutions RedHat curl-0:7.29.0-42.el7_4.2 *
Red Hat Enterprise Linux 7.5 Extended Update Support RedHat curl-0:7.29.0-46.el7_5.1 *
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 artful *
Curl Ubuntu bionic *
Curl Ubuntu devel *
Curl Ubuntu trusty *
Curl Ubuntu upstream *
Curl Ubuntu xenial *

Potential Mitigations

  • Use a language that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.

  • For example, many languages that perform their own memory management, such as Java and Perl, are not subject to buffer overflows. Other languages, such as Ada and C#, typically provide overflow protection, but the protection can be disabled by the programmer.

  • Be wary that a language’s interface to native code may still be subject to overflows, even if the language itself is theoretically safe.

  • Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.

  • Examples include the Safe C String Library (SafeStr) by Messier and Viega [REF-57], and the Strsafe.h library from Microsoft [REF-56]. These libraries provide safer versions of overflow-prone string-handling functions.

  • 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.

  • Consider adhering to the following rules when allocating and managing an application’s memory:

  • 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].

  • Use a CPU and operating system that offers Data Execution Protection (using hardware NX or XD bits) or the equivalent techniques that simulate this feature in software, such as PaX [REF-60] [REF-61]. These techniques ensure that any instruction executed is exclusively at a memory address that is part of the code segment.

  • For more information on these techniques see D3-PSEP (Process Segment Execution Prevention) from D3FEND [REF-1336].

References