NVD Vulnerability Detail
Search Exploit, PoC
CVE-2021-21309
Summary

Redis is an open-source, in-memory database that persists on disk. In affected versions of Redis an integer overflow bug in 32-bit Redis version 4.0 or newer could be exploited to corrupt the heap and potentially result with remote code execution. Redis 4.0 or newer uses a configurable limit for the maximum supported bulk input size. By default, it is 512MB which is a safe value for all platforms. If the limit is significantly increased, receiving a large request from a client may trigger several integer overflow scenarios, which would result with buffer overflow and heap corruption. We believe this could in certain conditions be exploited for remote code execution. By default, authenticated Redis users have access to all configuration parameters and can therefore use the “CONFIG SET proto-max-bulk-len” to change the safe default, making the system vulnerable. **This problem only affects 32-bit Redis (on a 32-bit system, or as a 32-bit executable running on a 64-bit system).** The problem is fixed in version 6.2, and the fix is back ported to 6.0.11 and 5.0.11. Make sure you use one of these versions if you are running 32-bit Redis. An additional workaround to mitigate the problem without patching the redis-server executable is to prevent clients from directly executing `CONFIG SET`: Using Redis 6.0 or newer, ACL configuration can be used to block the command. Using older versions, the `rename-command` configuration directive can be used to rename the command to a random string unknown to users, rendering it inaccessible. Please note that this workaround may have an additional impact on users or operational systems that expect `CONFIG SET` to behave in certain ways.

Publication Date Feb. 27, 2021, 7:15 a.m.
Registration Date Feb. 27, 2021, 10:02 a.m.
Last Update Nov. 21, 2024, 2:47 p.m.
CVSS3.1 : HIGH
スコア 8.8
Vector CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
攻撃元区分(AV) ネットワーク
攻撃条件の複雑さ(AC)
攻撃に必要な特権レベル(PR)
利用者の関与(UI) 不要
影響の想定範囲(S) 変更なし
機密性への影響(C)
完全性への影響(I)
可用性への影響(A)
CVSS2.0 : MEDIUM
Score 6.5
Vector AV:N/AC:L/Au:S/C:P/I:P/A:P
攻撃元区分(AV) ネットワーク
攻撃条件の複雑さ(AC)
攻撃前の認証要否(Au) 単一
機密性への影響(C)
完全性への影響(I)
可用性への影響(A)
Get all privileges. いいえ
Get user privileges いいえ
Get other privileges いいえ
User operation required いいえ
Affected software configurations
Configuration1 or higher or less more than less than
cpe:2.3:a:redislabs:redis:*:*:*:*:*:*:*:* 6.0.0 6.0.11
cpe:2.3:a:redislabs:redis:*:*:*:*:*:*:*:* 4.0 5.0.11
Related information, measures and tools
Common Vulnerabilities List

JVN Vulnerability Information
Redis における整数オーバーフローの脆弱性
Title Redis における整数オーバーフローの脆弱性
Summary

Redis には、整数オーバーフローの脆弱性が存在します。

Possible impacts 情報を取得される、情報を改ざんされる、およびサービス運用妨害 (DoS) 状態にされる可能性があります。
Solution

ベンダより正式な対策が公開されています。ベンダ情報を参照して適切な対策を実施してください。

Publication Date Feb. 22, 2021, midnight
Registration Date Nov. 18, 2021, 4:24 p.m.
Last Update Nov. 18, 2021, 4:24 p.m.
Affected System
Redis
Redis 
CVE (情報セキュリティ 共通脆弱性識別子)
CWE (共通脆弱性タイプ一覧)
ベンダー情報
Change Log
No Changed Details Date of change
1 [2021年11月18日]
  掲載
Nov. 18, 2021, 4:24 p.m.