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fstec логотип

BDU:2025-00812

Опубликовано: 14 мая 2021
Источник: fstec
CVSS3: 5.5
CVSS2: 4.6
EPSS Низкий

Описание

Уязвимость функции hfsplus_file_truncate() компонента fs/hfsplus/extents.c ядра операционной системы Linux связана с одновременным выполнением с использованием общего ресурса с неправильной синхронизацией. Эксплуатация уязвимости может позволить нарушителю вызвать отказ в обслуживании

Вендор

Canonical Ltd.
ООО «РусБИТех-Астра»
Сообщество свободного программного обеспечения

Наименование ПО

Ubuntu
Astra Linux Special Edition для «Эльбрус»
Debian GNU/Linux
Linux

Версия ПО

18.04 LTS (Ubuntu)
8.1 «Ленинград» (Astra Linux Special Edition для «Эльбрус»)
20.04 LTS (Ubuntu)
11 (Debian GNU/Linux)
12 (Debian GNU/Linux)
от 5.0 до 5.4.120 (Linux)
от 5.11 до 5.11.22 (Linux)
от 5.12 до 5.12.5 (Linux)
от 5.5 до 5.10.38 (Linux)
от 4.19 rc1 до 4.19.191 (Linux)
от 5.13 до 5.13 rc2 (Linux)

Тип ПО

Операционная система

Операционные системы и аппаратные платформы

Canonical Ltd. Ubuntu 18.04 LTS
ООО «РусБИТех-Астра» Astra Linux Special Edition для «Эльбрус» 8.1 «Ленинград»
Canonical Ltd. Ubuntu 20.04 LTS
Сообщество свободного программного обеспечения Debian GNU/Linux 11
Сообщество свободного программного обеспечения Debian GNU/Linux 12
Сообщество свободного программного обеспечения Linux от 5.0 до 5.4.120
Сообщество свободного программного обеспечения Linux от 5.11 до 5.11.22
Сообщество свободного программного обеспечения Linux от 5.12 до 5.12.5
Сообщество свободного программного обеспечения Linux от 5.5 до 5.10.38
Сообщество свободного программного обеспечения Linux от 4.19 rc1 до 4.19.191
Сообщество свободного программного обеспечения Linux от 5.13 до 5.13 rc2

Уровень опасности уязвимости

Средний уровень опасности (базовая оценка CVSS 2.0 составляет 4,6)
Средний уровень опасности (базовая оценка CVSS 3.0 составляет 5,5)

Возможные меры по устранению уязвимости

В условиях отсутствия обновлений безопасности от производителя рекомендуется придерживаться "Рекомендаций по безопасной настройке операционных систем LINUX", изложенных в методическом документе ФСТЭК России, утверждённом 25 декабря 2022 года.
Использование рекомендаций:
Для Linux:
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=c3187cf32216313fb316084efac4dab3a8459b1d
Для Debian GNU/Linux:
https://security-tracker.debian.org/tracker/CVE-2021-46989
Для Ubuntu:
https://ubuntu.com/security/CVE-2021-46989
Для ОС Astra Linux:
https://wiki.astralinux.ru/astra-linux-se81-bulletin-20241206SE81

Статус уязвимости

Подтверждена производителем

Наличие эксплойта

Данные уточняются

Информация об устранении

Уязвимость устранена

Идентификаторы других систем описаний уязвимостей

EPSS

Процентиль: 1%
0.00012
Низкий

5.5 Medium

CVSS3

4.6 Medium

CVSS2

Связанные уязвимости

CVSS3: 5.5
ubuntu
почти 2 года назад

In the Linux kernel, the following vulnerability has been resolved: hfsplus: prevent corruption in shrinking truncate I believe there are some issues introduced by commit 31651c607151 ("hfsplus: avoid deadlock on file truncation") HFS+ has extent records which always contains 8 extents. In case the first extent record in catalog file gets full, new ones are allocated from extents overflow file. In case shrinking truncate happens to middle of an extent record which locates in extents overflow file, the logic in hfsplus_file_truncate() was changed so that call to hfs_brec_remove() is not guarded any more. Right action would be just freeing the extents that exceed the new size inside extent record by calling hfsplus_free_extents(), and then check if the whole extent record should be removed. However since the guard (blk_cnt > start) is now after the call to hfs_brec_remove(), this has unfortunate effect that the last matching extent record is removed unconditionally. To reproduce thi...

CVSS3: 5.5
redhat
почти 2 года назад

In the Linux kernel, the following vulnerability has been resolved: hfsplus: prevent corruption in shrinking truncate I believe there are some issues introduced by commit 31651c607151 ("hfsplus: avoid deadlock on file truncation") HFS+ has extent records which always contains 8 extents. In case the first extent record in catalog file gets full, new ones are allocated from extents overflow file. In case shrinking truncate happens to middle of an extent record which locates in extents overflow file, the logic in hfsplus_file_truncate() was changed so that call to hfs_brec_remove() is not guarded any more. Right action would be just freeing the extents that exceed the new size inside extent record by calling hfsplus_free_extents(), and then check if the whole extent record should be removed. However since the guard (blk_cnt > start) is now after the call to hfs_brec_remove(), this has unfortunate effect that the last matching extent record is removed unconditionally. To reproduce thi...

CVSS3: 5.5
nvd
почти 2 года назад

In the Linux kernel, the following vulnerability has been resolved: hfsplus: prevent corruption in shrinking truncate I believe there are some issues introduced by commit 31651c607151 ("hfsplus: avoid deadlock on file truncation") HFS+ has extent records which always contains 8 extents. In case the first extent record in catalog file gets full, new ones are allocated from extents overflow file. In case shrinking truncate happens to middle of an extent record which locates in extents overflow file, the logic in hfsplus_file_truncate() was changed so that call to hfs_brec_remove() is not guarded any more. Right action would be just freeing the extents that exceed the new size inside extent record by calling hfsplus_free_extents(), and then check if the whole extent record should be removed. However since the guard (blk_cnt > start) is now after the call to hfs_brec_remove(), this has unfortunate effect that the last matching extent record is removed unconditionally. To reproduce

CVSS3: 5.5
debian
почти 2 года назад

In the Linux kernel, the following vulnerability has been resolved: h ...

CVSS3: 5.5
github
почти 2 года назад

In the Linux kernel, the following vulnerability has been resolved: hfsplus: prevent corruption in shrinking truncate I believe there are some issues introduced by commit 31651c607151 ("hfsplus: avoid deadlock on file truncation") HFS+ has extent records which always contains 8 extents. In case the first extent record in catalog file gets full, new ones are allocated from extents overflow file. In case shrinking truncate happens to middle of an extent record which locates in extents overflow file, the logic in hfsplus_file_truncate() was changed so that call to hfs_brec_remove() is not guarded any more. Right action would be just freeing the extents that exceed the new size inside extent record by calling hfsplus_free_extents(), and then check if the whole extent record should be removed. However since the guard (blk_cnt > start) is now after the call to hfs_brec_remove(), this has unfortunate effect that the last matching extent record is removed unconditionally. To reprodu...

EPSS

Процентиль: 1%
0.00012
Низкий

5.5 Medium

CVSS3

4.6 Medium

CVSS2