CVE-2020-26263

Katalog CVE

CVSS 7.5 · High EPSS 1,5%

Kerentanan Inadequate Encryption Strength pada tlslite-ng project tlslite-ng. Skor CVSS 3.1 7.5 (High) menurut NVD.

Deskripsi (NVD)

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.

Rincian

Terbit di NVD

21 Desember 2020

Terakhir diubah

17 Juni 2026

Status NVD

Modified

CVSS 3.1

7.5 (High), sumber NVD
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N · uraikan di kalkulator

Jenis kelemahan (CWE)

CWE-326: Inadequate Encryption Strength

EPSS (30 hari)

1,5% peluang dieksploitasi; lebih tinggi dari 73,9% CVE lain

Produk dan versi terdampak

> Data dari konfigurasi CPE di NVD.

Referensi dan perbaikan

• https://github.com/tlsfuzzer/tlslite-ng/commit/c28d6d387bba59d8bd5cb3ba15edc42edf54b368 patch · advisory pihak ketiga
• https://github.com/tlsfuzzer/tlslite-ng/pull/438 patch · advisory pihak ketiga
• https://github.com/tlsfuzzer/tlslite-ng/pull/439 patch · advisory pihak ketiga
• https://github.com/tlsfuzzer/tlslite-ng/security/advisories/GHSA-wvcv-832q-fjg7 exploit · patch · advisory pihak ketiga
• https://pypi.org/project/tlslite-ng/ product · advisory pihak ketiga
• https://securitypitfalls.wordpress.com/2018/08/03/constant-time-compare-in-python/ exploit · advisory pihak ketiga