CVE-2023-4156

A heap out-of-bounds read flaw was found in builtin.c in the gawk package. This issue may lead to a crash and could be used to read sensitive information.

A heap out-of-bounds read flaw was found in builtin.c in the gawk package. This issue may lead to a crash and could be used to read sensitive information.

The gawk package is the GNU implementation of awk. The awk utility interprets a special-purpose programming language that makes it possible to handle simple data-reformatting jobs with just a few lines of code.

Security Fix(es):

A heap out of bound read issue exists in builtin.c of gawk prior to version 5.1.1. The array "the_args" takes an unsafe index "val", while it does not validate the index to ensure the index refers to a valid position in the array (e.g., exceedingly large or negative). The vulnerability can cause crash of the software and might be used by attackers to read sensitive information.

https://mail.gnu.org/archive/html/bug-gawk/2022-08/msg00000.html https://mail.gnu.org/archive/html/bug-gawk/2022-08/msg00023.html https://fossies.org/linux/gawk/ChangeLog#470 (Line: 470-475)(CVE-2023-4156)

A heap out-of-bounds read flaw was found in builtin.c in the gawk package. This issue may lead to a crash and could be used to read sensitive information.

• Fix CVE-2023-4156: builtin.c (format_tree): When collecting positional field widths or precisions, check for wrap around to negative values.

• CVE-2023-4156: fix heap out-of-bounds read flaw in builtin.c to prevent potential crash and information leakage

• CVE-2023-4156: fix heap out-of-bounds read flaw in builtin.c to prevent potential crash and information leakage

• Fix CVE-2023-4156: builtin.c (format_tree): When collecting positional field widths or precisions, check for wrap around to negative values.

• CVE-2023-4156: builtin.c (format_tree): when collecting positional field widths or precisions, check for wrap around to negative values
• CVE-2026-40469: builtin.c (sub_common): check for overflow in the result buffer size calculation using 64-bit math, failing with a fatal error instead of corrupting the heap on 32-bit builds

• CVE-2023-4156: builtin.c (format_tree): when collecting positional field widths or precisions, check for wrap around to negative values
• CVE-2026-40469: builtin.c (sub_common): check for overflow in the result buffer size calculation using 64-bit math, failing with a fatal error instead of corrupting the heap on 32-bit builds

This update for gawk fixes the following issues:

• CVE-2023-4156: Fix a heap out of bound read by validating the index into argument list. (bsc#1214025)

This update for gawk fixes the following issues:

• CVE-2023-4156: Fix a heap out of bound read by validating the index into argument list. (bsc#1214025)

It was discovered that gawk could be made to read out of bounds when processing certain inputs. If a user or an automated system were tricked into opening a specially crafted input, an attacker could possibly use this issue to cause a denial of service.