{"id":123495,"date":"2025-04-14T09:05:08","date_gmt":"2025-04-14T07:05:08","guid":{"rendered":"https:\/\/prohoster.info\/blog\/novosti-interneta\/perepolnenie-bufera-v-perl-svyazannoe-s-obrabotkoj-simvolov"},"modified":"2025-04-14T09:05:08","modified_gmt":"2025-04-14T07:05:08","slug":"perepolnenie-bufera-v-perl-svyazannoe-s-obrabotkoj-simvolov","status":"publish","type":"post","link":"https:\/\/prohoster.info\/en\/blog\/news\/perepolnenie-bufera-v-perl-svyazannoe-s-obrabotkoj-simvolov","title":{"rendered":"Buffer overflow in Perl related to character handling","gt_translate_keys":[{"key":"rendered","format":"text"}]},"content":{"rendered":"
Corrective updates for Perl interpreter versions 5.40.2 and 5.38.4 have been released, addressing a vulnerability (CVE-2024-56406) that leads to a buffer overflow when transliterating specifically crafted non-ASCII characters using the \"tr..\/..\" operator. There is a possibility of exploiting this vulnerability to execute arbitrary code in the system. The issue has been present in stable releases of Perl since 2021, affecting the branches 5.34, 5.36, 5.38, and 5.40. The resolution of the vulnerability in distributions can be monitored on the following pages: Debian, Ubuntu, Fedora, Arch, FreeBSD. Distributions based on RHEL 9, SUSE 15, and openSUSE Leap 15.6 are not affected by the vulnerability, as they include Perl versions 5.32 and 5.26. <\/p>\n
The vulnerability affects programs that use unverified external data on the left side of the \"tr\" operator, where a variable is specified with data for replacing characters (for example, \"$external_string =~ tr\/a\/b\/\"). In the function S_do_trans_invmap(), which processes the operator, accessing memory outside the allocated buffer occurs when handling certain non-ASCII bytes. The overflow arises because some byte sequences in the source data may be converted into UTF-8 sequences, which require two bytes instead of one. <\/p>\n
It is noteworthy that the vulnerability arose after a change implemented in 2020 that removed the additional check for sufficient memory allocation on the pretext that when calculating size, rounding up was sufficient. To check for the vulnerability, you can execute the following code: perl -e '$_ = \"\\x{FF}\" x 1000000; tr\/\\xFF\/\\x{100}\/;' Segmentation fault (core dumped) \n Source: opennet.ru<\/a> <\/p>","protected":false,"gt_translate_keys":[{"key":"rendered","format":"html"}]},"excerpt":{"rendered":"