CVE-2020-26263
RSA weakness in tslite-ng
描述
tlslite-ng is an open source python library that implements SSL and TLS cryptographic protocols. In tlslite-ng before versions 0.7.6 and 0.8.0-alpha39, the code that performs decryption and padding check in RSA PKCS#1 v1.5 decryption is data dependant. In particular, the code has multiple ways in which it leaks information about the decrypted ciphertext. It aborts as soon as the plaintext doesn't start with 0x00, 0x02. All TLS servers that enable RSA key exchange as well as applications that use the RSA decryption API directly are vulnerable. This is patched in versions 0.7.6 and 0.8.0-alpha39. Note: the patches depend on Python processing the individual bytes in side-channel free manner, this is known to not the case (see reference). As such, users that require side-channel resistance are recommended to use different TLS implementations, as stated in the security policy of tlslite-ng.
如何修補 CVE-2020-26263
要修補 CVE-2020-26263,請將受影響套件升級到下列已修補版本。
- —升級至 0.7.6 或更新版本
- —升級至 c28d6d387bba59d8bd5cb3ba15edc42edf54b368 或更新版本
CVE-2020-26263 正在被利用嗎?
低 — EPSS 為 0.2%,目前沒有觀察到大規模利用活動。
受影響套件(2)
- from 0, < 0.7.6
- from 0, < c28d6d387bba59d8bd5cb3ba15edc42edf54b368 | from 0, < 0.7.6
CVSS 分數
| 來源 | 版本 | 嚴重程度 | 向量 |
|---|---|---|---|
| osv | CVSS 4.0 | — | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N |
| osv | CVSS 3.1 | HIGH7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N |