In LibSass 3.5.5, a NULL Pointer Dereference in the function Sass::Selector_List::populate_extends in SharedPtr.hpp (used by ast.cpp and ast_selectors.cpp) may cause a Denial of Service (application crash) via a crafted sass input file.
Weakness
The product dereferences a pointer that it expects to be valid but is NULL.
Affected Software
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Libsass | Sass-lang | 3.5.5 (including) | 3.5.5 (including) |
| Libsass | Ubuntu | bionic | * |
| Libsass | Ubuntu | cosmic | * |
| Libsass | Ubuntu | disco | * |
| Libsass | Ubuntu | eoan | * |
| Libsass | Ubuntu | esm-apps/bionic | * |
| Libsass | Ubuntu | esm-apps/xenial | * |
| Libsass | Ubuntu | groovy | * |
| Libsass | Ubuntu | hirsute | * |
| Libsass | Ubuntu | impish | * |
| Libsass | Ubuntu | kinetic | * |
| Libsass | Ubuntu | lunar | * |
| Libsass | Ubuntu | mantic | * |
| Libsass | Ubuntu | upstream | * |
| Libsass | Ubuntu | xenial | * |
Potential Mitigations
References
- http://lists.opensuse.org/opensuse-security-announce/2019-07/msg00047.html
- http://lists.opensuse.org/opensuse-security-announce/2019-07/msg00051.html
- http://lists.opensuse.org/opensuse-security-announce/2019-08/msg00027.html
- https://github.com/sass/libsass/issues/2779
- http://lists.opensuse.org/opensuse-security-announce/2019-07/msg00047.html
- http://lists.opensuse.org/opensuse-security-announce/2019-07/msg00051.html
- http://lists.opensuse.org/opensuse-security-announce/2019-08/msg00027.html
- https://github.com/sass/libsass/issues/2779