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.

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

  - 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. (CVE-2020-26263)

Note that Nessus relies on the presence of the package as reported by the vendor.

There are packages installed that are affected by a vulnerability referenced in the following CVE:

  - 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. (CVE-2020-26263)

ID	Name	Product	Family	Type	Severity
262588	Linux Distros Unpatched Vulnerability : CVE-2020-26263	Nessus	Misc.	Local	high
420127	SCA: security update for tlslite-ng (GHSA-wvcv-832q-fjg7)	Tenable Cloud Security	SCA Checks	Local	high
420127	SCA: security update for tlslite-ng (GHSA-wvcv-832q-fjg7)	Tenable Self-Hosted Container Security	SCA Checks	Local	high

Detections

Analytics

CVE-2020-26263

high

Tenable Plugins

high

high

high