Bug 1835377 (CVE-2020-12825)
| Summary: | CVE-2020-12825 libcroco: Stack overflow in function cr_parser_parse_any_core in cr-parser.c | ||
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| Product: | [Other] Security Response | Reporter: | Pedro Sampaio <psampaio> |
| Component: | vulnerability | Assignee: | Red Hat Product Security <security-response-team> |
| Status: | CLOSED ERRATA | QA Contact: | |
| Severity: | medium | Docs Contact: | |
| Priority: | medium | ||
| Version: | unspecified | CC: | aubaker, caillon+fedoraproject, cwarfiel, dchong, dodji, ekirby, eng-i18n-bugs, fmuellner, gnome-sig, jastephe, jhorak, john.j5live, lcaparel, mcatanza, mclasen, mmezynsk, nmadhesh, otaylor, petersen, rhughes, rstrode, rsunog, sandmann, sbalasub, simore, stransky, suanand, tcrider, tpopela |
| Target Milestone: | --- | Keywords: | Security |
| Target Release: | --- | ||
| Hardware: | All | ||
| OS: | Linux | ||
| Whiteboard: | |||
| Fixed In Version: | Doc Type: | If docs needed, set a value | |
| Doc Text: |
A stack overflow flaw was found in libcroco. A service using libcroco's CSS parser could be crashed by a local, authenticated attacker, or an attacker utilizing social engineering, using a crafted input. The highest threat from this vulnerability is to system availability.
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Story Points: | --- |
| Clone Of: | Environment: | ||
| Last Closed: | 2020-09-30 03:57:10 UTC | Type: | --- |
| Regression: | --- | Mount Type: | --- |
| Documentation: | --- | CRM: | |
| Verified Versions: | Category: | --- | |
| oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | |
| Cloudforms Team: | --- | Target Upstream Version: | |
| Embargoed: | |||
| Bug Depends On: | 1835378, 1835379, 1835950, 1835951, 1862569, 1862570, 1866484, 1866540, 1866541, 1910594 | ||
| Bug Blocks: | 1835380 | ||
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Description
Pedro Sampaio
2020-05-13 17:32:06 UTC
Created libcroco tracking bugs for this issue: Affects: fedora-all [bug 1835378] Created mingw-libcroco tracking bugs for this issue: Affects: fedora-all [bug 1835379] libcroco has a CSS2 parser which uses the function cr_parser_parse_any_core() in cr-parser.c to parse CSS "any" grammar. The function calls itself recursively when the tokenizer provides it with a token which is one of type: PO_TK (Opening parenthesis), BO_TK (Opening bracket), or FUNCTION_TK. It does not limit the recursion and thus is susceptible to a stack overflow when crafted input is provided to the CSS parser. Mitigation: To mitigate this flaw as it applies to gnome-shell, do not install untrusted gnome-shell extensions or themes. Red Hat Enterprise Linux does not ship with gnome-shell themes that will trigger this vulnerability. To mitigate this flaw as it applies to inkscape, do not open untrusted CSS in inkscape. Statement: While Red Hat Enterprise Linux 6, 7 and 8 ship versions of `libcroco` that are vulnerable to this flaw, the packages which use this library as a dependency would require a user to open a malicious file locally for exploitation. Opening such a file may result in a temporary crash of the application. See below for more detailed information: * Red Hat Enterprise Linux 8 - `libcroco` is a runtime dependency of `gnome-shell`, `gettext` and `inkscape`. * Red Hat Enterprise Linux 7 - `libcroco` is a runtime dependency of `gnome-shell`, `gettext`, `librsvg2` and `inkscape`. * Red Hat Enterprise Linux 6 - `libcroco` is required by `firefox` to bundle `gtk3` but `firefox` does not use `libcroco` as its CSS parsing engine or provide gtk3 to other packages, and thus not affected. `libcroco` is a runtime dependency of `inkscape`, `librsvg2` and `gettext`. This flaw has only been demonstrated to cause a crash, but if there is any concern of further exploitation beyond that, Red Hat Enterprise Linux 6, 7, and 8 packages are built with a stack protector and stack ASLR which would significantly reduce the likelihood of further exploitation. This issue has been addressed in the following products: Red Hat Enterprise Linux 8 Via RHSA-2020:3654 https://access.redhat.com/errata/RHSA-2020:3654 This issue has been addressed in the following products: Red Hat Enterprise Linux 7 Via RHSA-2020:4072 https://access.redhat.com/errata/RHSA-2020:4072 This bug is now closed. Further updates for individual products will be reflected on the CVE page(s): https://access.redhat.com/security/cve/cve-2020-12825 |