Multiple NULL pointer dereference vulnerabilities in newlib
| CENSUS ID: | CENSUS-2020-0001 |
| CVE IDs: | CVE-2019-14871, CVE-2019-14872, CVE-2019-14873, CVE-2019-14874, CVE-2019-14875, CVE-2019-14876, CVE-2019-14877, CVE-2019-14878 |
| Affected Products: | newlib versions prior to 3.3.0, its derivatives (e.g. newlib-nano, picolibc and related Platform SDKs such as " GNU ARM Embedded Toolchain 64-bit Linux 8-2018-q4-major") |
| Class: | NULL pointer dereference (CWE-476) |
| Discovered by: | Dimitrios Glynos |
During the security assessment of a firmware binary a number of NULL pointer dereference bugs were found caused by newlib-nano code. newlib-nano is a C library for use on 32-bit processors that have only a few kB of memory. It turns out that newlib-nano was part of the "GNU ARM Embedded Toolchain" that the chip manufacturer (Microchip/Atmel) delivered for application development purposes. newlib-nano inherits code from the newlib project, which is a C library intended for use on embedded systems. All NULL pointer dereference bugs identified in newlib-nano were inherited by newlib code and therefore CENSUS reported the respective vulnerabilities to the upstream project. Users of the newlib library are advised to update to version 3.3.0 and make sure to build the library sources with the newlib-reent-check-verify 'configure' option enabled.
shadow v2 public release
About four months ago (April 2017), Vasilis Tsaousoglou and myself presented our work on exploiting Android's libc allocator at the 2017 INFILTRATE conference (Miami, Florida). Since version 5.0, Android has adopted the jemalloc allocator as its default libc malloc(3) implementation. For our talk we extended our previously released jemalloc heap exploration and exploitation tool called 'shadow' to support Android (both ARM32 and ARM64), and demonstrated its use on understanding the impact of libc heap corruption vulnerabilities. We also presented new jemalloc/Android-specific exploitation techniques for double free and arbitrary free vulnerabilities.
INFILTRATE 2017
CENSUS researchers Vasilis Tsaousoglou and Patroklos Argyroudis delivered the "The Shadow over Android: Heap Exploitation Assistance for Android's libc Allocator" technical talk at the 2017 INFILTRATE (Miami, Florida) conference. The abstract of the talk follows: