Bug 1766617 (CVE-2019-17595) - CVE-2019-17595 ncurses: heap-based buffer overflow in the fmt_entry function in tinfo/comp_hash.c
Summary: CVE-2019-17595 ncurses: heap-based buffer overflow in the fmt_entry function ...
Alias: CVE-2019-17595
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
Target Milestone: ---
Assignee: Red Hat Product Security
QA Contact:
Depends On: 1766618 1785703 1785704
Blocks: 1766620
TreeView+ depends on / blocked
Reported: 2019-10-29 14:03 UTC by Guilherme de Almeida Suckevicz
Modified: 2021-11-09 18:44 UTC (History)
2 users (show)

Fixed In Version:
Doc Type: If docs needed, set a value
Doc Text:
Clone Of:
Last Closed: 2021-10-25 09:55:57 UTC

Attachments (Terms of Use)

System ID Private Priority Status Summary Last Updated
Red Hat Product Errata RHSA-2021:4426 0 None None None 2021-11-09 18:44:45 UTC

Description Guilherme de Almeida Suckevicz 2019-10-29 14:03:49 UTC
There is a heap-based buffer over-read in the fmt_entry function in tinfo/comp_hash.c in the terminfo library in ncurses before 6.1-20191012.


Comment 1 Guilherme de Almeida Suckevicz 2019-10-29 14:04:05 UTC
Created ncurses tracking bugs for this issue:

Affects: fedora-all [bug 1766618]

Comment 3 Marco Benatto 2019-12-20 15:05:12 UTC
Upstream commit for this issue:


 ncurses 6.1 - patch 20191012

+ amend recent changes to ncurses*-config and pc-files to filter out
  Debian linker-flags (report by Sven Joachim, cf: 20150516).
+ clarify relationship between tic, infocmp and captoinfo in manpage.
+ check for invalid hashcode in _nc_find_type_entry and
> fix several errata in tic (reports/testcases by "zjuchenyuan"):
+ check for invalid hashcode in _nc_find_entry.
+ check for missing character after backslash in fmt_entry
+ check for acsc with odd length in dump_entry in check for one-one
  mapping (cf: 20060415);
+ check length when converting from old AIX box_chars_1 capability,
  overlooked in changes to eliminate strcpy (cf: 20001007).
+ amend the ncurses*-config and pc-files to take into account the rpath

Comment 7 Marco Benatto 2019-12-20 18:55:03 UTC
There's an issue with ncurses library when using infotocap tool to read and dump terminal capabilities from terminfo files. A termeinfo file is a database which described terminal capabilities and screen operations used by several screen-oriented programs. When dumping terminfo data, infotocap parses the input file but misses to check NULL byte terminators on some scenarios leading to a heap-based buffer overflow by reading extra bytes beyond the allocated buffer. An attack may leverage this by crafting a special terminfo input file leading the application to crash, thus causing DoS, to dump extra bytes from heap causing a low confidentiality impact.

Comment 16 errata-xmlrpc 2021-11-09 18:44:44 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8

Via RHSA-2021:4426 https://access.redhat.com/errata/RHSA-2021:4426

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