SB2021121730 - Ubuntu update for python3.7

Description

This security bulletin contains information about 3 vulnerabilities.

1) Resource management error (CVE-ID: CVE-2020-8492)

CWE-ID: CWE-399 - Resource Management Errors

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:P/U:Green

The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to improper input validation in urllib.request.AbstractBasicAuthHandler when processing HTTP responses. A remote attacker who controls a HTTP server can send a specially crafted HTTP response to the client application and conduct Regular Expression Denial of Service (ReDoS) attack.

2) Resource management error (CVE-ID: CVE-2021-3733)

CWE-ID: CWE-399 - Resource Management Errors

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:U/U:Clear

The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to improper management of internal resources within the application within the AbstractBasicAuthHandler class in urllib. A remote attacker with control over the server can perform regular expression denial of service attack during authentication.

3) Infinite loop (CVE-ID: CVE-2021-3737)

CWE-ID: CWE-835 - Loop with Unreachable Exit Condition ('Infinite Loop')

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:U/U:Clear

The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to infinite loop. A remote attacker who controls a malicious server can force the client to enter an infinite loop on a 100 Continue response.

Remediation

Install update from vendor's website.

References

• https://ubuntu.com/security/notices/USN-5200-1