CVE-2021-3449
NULL pointer deref in signature_algorithms processing
描述
An OpenSSL TLS server may crash if sent a maliciously crafted renegotiation ClientHello message from a client. If a TLSv1.2 renegotiation ClientHello omits the signature_algorithms extension (where it was present in the initial ClientHello), but includes a signature_algorithms_cert extension then a NULL pointer dereference will result, leading to a crash and a denial of service attack. A server is only vulnerable if it has TLSv1.2 and renegotiation enabled (which is the default configuration). OpenSSL TLS clients are not impacted by this issue. All OpenSSL 1.1.1 versions are affected by this issue. Users of these versions should upgrade to OpenSSL 1.1.1k. OpenSSL 1.0.2 is not impacted by this issue. Fixed in OpenSSL 1.1.1k (Affected 1.1.1-1.1.1j).
如何修補 CVE-2021-3449
要修補 CVE-2021-3449,請將受影響套件升級到下列已修補版本。
- —升級至 1.1.1k-r0 或更新版本
- —升級至 1.1.1k-r0 或更新版本
CVE-2021-3449 正在被利用嗎?
可能 — EPSS 為 62.9%,屬於高被利用機率區間,建議優先修補。
受影響套件(2)
- >= 1.1.1, < 1.1.1k-r0
- from 0, < 1.1.1k-r0
CVSS 分數
| 來源 | 版本 | 嚴重程度 | 向量 |
|---|---|---|---|
| osv | CVSS 3.1 | MEDIUM5.9 | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H |