CVE-2020-13757

Publication date 1 June 2020

Last updated 25 August 2025

Ubuntu priority

Medium

Why this priority?

Cvss 3 Severity Score

7.5 · High

Score breakdown

Description

Python-RSA before 4.1 ignores leading ‘\0’ bytes during decryption of ciphertext. This could conceivably have a security-relevant impact, e.g., by helping an attacker to infer that an application uses Python-RSA, or if the length of accepted ciphertext affects application behavior (such as by causing excessive memory allocation).

Status

Package Ubuntu Release Status
python-rsa 25.04 plucky
Not affected
24.10 oracular
Not affected
24.04 LTS noble
Not affected
23.10 mantic
Not affected
23.04 lunar
Not affected
22.10 kinetic
Not affected
22.04 LTS jammy
Not affected
21.10 impish Ignored end of life
21.04 hirsute Ignored end of life
20.10 groovy Ignored end of life
20.04 LTS focal
Fixed 4.0-3ubuntu0.1~esm1
19.10 eoan Ignored end of life
18.04 LTS bionic
Fixed 3.4.2-1ubuntu0.1~esm1
16.04 LTS xenial
Fixed 3.2.3-1.1ubuntu0.1~esm1
14.04 LTS trusty
Fixed 3.1.2-1ubuntu0.1+esm1

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Severity score breakdown

Parameter Value
Base score 7.5 · High
Attack vector Network
Attack complexity Low
Privileges required None
User interaction None
Scope Unchanged
Confidentiality High
Integrity impact None
Availability impact None
Vector CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

References

Related Ubuntu Security Notices (USN)

    • USN-4478-1
    • Python-RSA vulnerability
    • 31 August 2020
    • USN-4478-2
    • Python-RSA vulnerability
    • 21 February 2022

Other references