grub2-2.02-90.1.0.1.el8
エラータID: AXSA:2021-1565:02
リリース日:
2021/03/08 Monday - 14:08
題名:
grub2-2.02-90.1.0.1.el8
影響のあるチャネル:
Asianux Server 8 for x86_64
Severity:
Moderate
Description:
- grub2には、セキュアブートが有効なとき誤ってACPIコマンドを有効にするため、
特権を持つ攻撃者が ACPI の SSDT (Secondary System Description Table)
にLinuxカーネルのロックダウン変数を上書きするコードを埋め込むように細工する
ことで、セキュアブートを迂回してサインされていないコードを動かすことが可能な
脆弱性があります。(CVE-2020-14372)
- grub2には、rmmodの実装において、依存モジュールとして使用されている
モジュールを、他の依存モジュールがまだロードされているかチェックせずに
アンロードしてしまうために解放後使用が発生し、任意のコードを実行したり、
セキュアブートの保護をバイパスできてしまう脆弱性があります。(CVE-2020-25632)
- grub2には、USBデバイスの初期化中にほとんど境界値チェックを行わないため、
攻撃者がメモリデータを破壊して任意のコードを実行し、セキュアブートの
メカニズムをバイパスできる脆弱性があります。(CVE-2020-25647)
- grub2 には、与えられたコマンドライン引数を対応する内容に展開する際、
十分な境界チェックを行わずに 1kB のスタックバッファーを一時記憶領域
として使用するため、大きなペイロードを持つ変数を参照するコマンドラインを
使用して関数を呼び出すと、スタックバッファーがオーバーフローし、
スタックフレームが破壊され、セキュアブートの保護を回避するよう制御
されてしまう脆弱性があります。(CVE-2020-27749)
- grub2 の cutmem コマンドは、セキュアブートのロックを無視して
grub のメモリレイアウトを適切にトリアージした後にセキュアブートの
保護を回避する機会を作るため、特権を持つ攻撃者がアドレス範囲をメモリ
から削除できてしまう脆弱性があります。(CVE-2020-27779)
- grub2 の オプションパーサーには、攻撃者が特定のコマンドを大量の短い形式の
オプションと一緒に呼ぶことによって、元々ヒープに割り当たられたバッファーの
終端への書き込みを許してしまう脆弱性があります。(CVE-2021-20225)
- grub2には、メニューをレンダリングする Setparam_prefix()関数内の
長さの計算処理に、クオートされたシングルクオートを表現するのに3文字が
必要と仮定していましたが、実際には4文字必要だったため、攻撃者が、1つの
クオートごとにメモリ内データを1バイト破壊することが可能な脆弱性があり
ます。(CVE-2021-20233)
解決策:
パッケージをアップデートしてください。
CVE:
CVE-2020-14372
A flaw was found in grub2 in versions prior to 2.06, where it incorrectly enables the usage of the ACPI command when Secure Boot is enabled. This flaw allows an attacker with privileged access to craft a Secondary System Description Table (SSDT) containing code to overwrite the Linux kernel lockdown variable content directly into memory. The table is further loaded and executed by the kernel, defeating its Secure Boot lockdown and allowing the attacker to load unsigned code. The highest threat from this vulnerability is to data confidentiality and integrity, as well as system availability.
A flaw was found in grub2 in versions prior to 2.06, where it incorrectly enables the usage of the ACPI command when Secure Boot is enabled. This flaw allows an attacker with privileged access to craft a Secondary System Description Table (SSDT) containing code to overwrite the Linux kernel lockdown variable content directly into memory. The table is further loaded and executed by the kernel, defeating its Secure Boot lockdown and allowing the attacker to load unsigned code. The highest threat from this vulnerability is to data confidentiality and integrity, as well as system availability.
CVE-2020-25632
A flaw was found in grub2 in versions prior to 2.06. The rmmod implementation allows the unloading of a module used as a dependency without checking if any other dependent module is still loaded leading to a use-after-free scenario. This could allow arbitrary code to be executed or a bypass of Secure Boot protections. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability.
A flaw was found in grub2 in versions prior to 2.06. The rmmod implementation allows the unloading of a module used as a dependency without checking if any other dependent module is still loaded leading to a use-after-free scenario. This could allow arbitrary code to be executed or a bypass of Secure Boot protections. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability.
CVE-2020-25647
A flaw was found in grub2 in versions prior to 2.06. During USB device initialization, descriptors are read with very little bounds checking and assumes the USB device is providing sane values. If properly exploited, an attacker could trigger memory corruption leading to arbitrary code execution allowing a bypass of the Secure Boot mechanism. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability.
A flaw was found in grub2 in versions prior to 2.06. During USB device initialization, descriptors are read with very little bounds checking and assumes the USB device is providing sane values. If properly exploited, an attacker could trigger memory corruption leading to arbitrary code execution allowing a bypass of the Secure Boot mechanism. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability.
CVE-2020-27749
A flaw was found in grub2 in versions prior to 2.06. Variable names present are expanded in the supplied command line into their corresponding variable contents, using a 1kB stack buffer for temporary storage, without sufficient bounds checking. If the function is called with a command line that references a variable with a sufficiently large payload, it is possible to overflow the stack buffer, corrupt the stack frame and control execution which could also circumvent Secure Boot protections. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability.
A flaw was found in grub2 in versions prior to 2.06. Variable names present are expanded in the supplied command line into their corresponding variable contents, using a 1kB stack buffer for temporary storage, without sufficient bounds checking. If the function is called with a command line that references a variable with a sufficiently large payload, it is possible to overflow the stack buffer, corrupt the stack frame and control execution which could also circumvent Secure Boot protections. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability.
CVE-2020-27779
A flaw was found in grub2 in versions prior to 2.06. The cutmem command does not honor secure boot locking allowing an privileged attacker to remove address ranges from memory creating an opportunity to circumvent SecureBoot protections after proper triage about grub's memory layout. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability.
A flaw was found in grub2 in versions prior to 2.06. The cutmem command does not honor secure boot locking allowing an privileged attacker to remove address ranges from memory creating an opportunity to circumvent SecureBoot protections after proper triage about grub's memory layout. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability.
CVE-2021-20225
A flaw was found in grub2 in versions prior to 2.06. The option parser allows an attacker to write past the end of a heap-allocated buffer by calling certain commands with a large number of specific short forms of options. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability.
A flaw was found in grub2 in versions prior to 2.06. The option parser allows an attacker to write past the end of a heap-allocated buffer by calling certain commands with a large number of specific short forms of options. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability.
CVE-2021-20233
A flaw was found in grub2 in versions prior to 2.06. Setparam_prefix() in the menu rendering code performs a length calculation on the assumption that expressing a quoted single quote will require 3 characters, while it actually requires 4 characters which allows an attacker to corrupt memory by one byte for each quote in the input. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability.
A flaw was found in grub2 in versions prior to 2.06. Setparam_prefix() in the menu rendering code performs a length calculation on the assumption that expressing a quoted single quote will require 3 characters, while it actually requires 4 characters which allows an attacker to corrupt memory by one byte for each quote in the input. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability.
追加情報:
N/A
ダウンロード:
SRPMS
- grub2-2.02-90.1.0.1.el8.src.rpm
MD5: 7c5d5832797c09dfebc190041d498a94
SHA-256: 20d375e312655ae03b56bc0533612e5b9d01d72303bc62d5c5ef821b69a6398a
Size: 7.55 MB
Asianux Server 8 for x86_64
- grub2-common-2.02-90.1.0.1.el8.noarch.rpm
MD5: f4915ae33773b5d43c6cd53c09583454
SHA-256: b3fffc7aca7f2f93b1df695e6e830a817e25aff1580a3fdba434a09bba16e4af
Size: 884.42 kB - grub2-efi-ia32-2.02-90.1.0.1.el8.x86_64.rpm
MD5: 3a70c55d776064443354e88974b74733
SHA-256: eb4e3eedb3006e0549ed07ec4cc14f805f57c428bb8ea421f80c739a10eb0be6
Size: 384.42 kB - grub2-efi-ia32-cdboot-2.02-90.1.0.1.el8.x86_64.rpm
MD5: ae484565675d9983cd4add4b7f0ca3c0
SHA-256: 4a0d74b3ea679c42a92de1d501a501a38733f139355bddc73931193949328159
Size: 1.15 MB - grub2-efi-ia32-modules-2.02-90.1.0.1.el8.noarch.rpm
MD5: 956514117f07c1d0074a7515f1a57a4b
SHA-256: 2652d204fbc5f328c6d30278e981117d8d9b198fb3c49c9f6a126db88ec2b78a
Size: 0.98 MB - grub2-efi-x64-2.02-90.1.0.1.el8.x86_64.rpm
MD5: 7df86fa94a550617bb369f1dfeff3467
SHA-256: 2d6e65bcf6b33f67dc5b3fe156af46414cea50d277908cddc4186e0398c34937
Size: 406.68 kB - grub2-efi-x64-cdboot-2.02-90.1.0.1.el8.x86_64.rpm
MD5: 0d6057d11399812c40a9f78613e94aef
SHA-256: b61548f72a05dde2efaa6c223e9e8d71a2dce646a39d29a27116358cd62717fe
Size: 1.17 MB - grub2-efi-x64-modules-2.02-90.1.0.1.el8.noarch.rpm
MD5: c69dfe0d988e61b86f8c3b838a69f245
SHA-256: 564c459a89f23116cbad3ee518bfc9a6df4699f44677407e5cec7f11400ab8da
Size: 1.01 MB - grub2-pc-2.02-90.1.0.1.el8.x86_64.rpm
MD5: 881b87758b24c751fb6c25df07b45b3b
SHA-256: 649cf2337fe0c2e9cd69e50794226ffe651b13bce5d4faba1e3ff13bc0a0703c
Size: 37.99 kB - grub2-tools-2.02-90.1.0.1.el8.x86_64.rpm
MD5: 6f2a6381928e494f7ae8f1fc3112db9f
SHA-256: 2ac6b940654e5176ac5b40ae9142c0601966249c6398c7c5f760ed5d06298ae5
Size: 1.96 MB - grub2-tools-efi-2.02-90.1.0.1.el8.x86_64.rpm
MD5: 701456cd2b6294cdfd497434c6c12870
SHA-256: 097691bacccebfe2af806b9f28c75c524b07862a7c43b8725edfd95ec52466d8
Size: 469.71 kB - grub2-tools-extra-2.02-90.1.0.1.el8.x86_64.rpm
MD5: 531ffb267888079750b8816665dd4a10
SHA-256: 129a029853e3005041c81cce925c6d951b2d9ccf193e6ecab18a3a091d2fdc50
Size: 1.06 MB - grub2-tools-minimal-2.02-90.1.0.1.el8.x86_64.rpm
MD5: 5f6e5237b422a5a603e41879251ae1e2
SHA-256: 8b597b993304ddf58198e62e5f575a65fb96a7b11f7ac9179828951d1076a415
Size: 204.59 kB - grub2-pc-modules-2.02-90.1.0.1.el8.noarch.rpm
MD5: fc2d7752ba62b9588d17795502e5d589
SHA-256: 97b38813cda6dabe132ded2558381cb70674200903fe7b7315f77567dc1e1523
Size: 867.13 kB
English