2026-01 Security Bulletin: Policy Enforcer: Multiple vulnerabilities in Python resolved in 24.1R3 release

Product Affected

This issue affects all versions of Policy Enforcer.

Severity

Critical

Severity Assessment (CVSS) Score

CVSS: v3.1: 9.8 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H)

Problem

Multiple vulnerabilities in the Juniper Networks Policy Enforcer have been resolved by updating the included version of Python from 2.7 to 3.10.

These issues affect Juniper Networks Policy Enforcer versions before 24.1R3.

Important security issues resolved include:

CVE	CVSS	Summary
CVE-2015-20107	7.6 (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:H/A:L)	In Python (aka CPython) up to 3.10.8, the mailcap module does not add escape characters into commands discovered in the system mailcap file. This may allow attackers to inject shell commands into applications that call mailcap.findmatch with untrusted input (if they lack validation of user-provided filenames or arguments). The fix is also back-ported to 3.7, 3.8, 3.9
CVE-2019-20907	7.5 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H)	In Lib/tarfile.py in Python through 3.8.3, an attacker is able to craft a TAR archive leading to an infinite loop when opened by tarfile.open, because _proc_pax lacks header validation.
CVE-2020-26116	7.2 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N)	http.client in Python 3.x before 3.5.10, 3.6.x before 3.6.12, 3.7.x before 3.7.9, and 3.8.x before 3.8.5 allows CRLF injection if the attacker controls the HTTP request method, as demonstrated by inserting CR and LF control characters in the first argument of HTTPConnection.request.
CVE-2020-8492	6.5 (CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H)	Python 2.7 through 2.7.17, 3.5 through 3.5.9, 3.6 through 3.6.10, 3.7 through 3.7.6, and 3.8 through 3.8.1 allows an HTTP server to conduct Regular Expression Denial of Service (ReDoS) attacks against a client because of urllib.request.AbstractBasicAuthHandler catastrophic backtracking.
CVE-2021-3177	9.8 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H)	Python 3.x through 3.9.1 has a buffer overflow in PyCArg_repr in _ctypes/callproc.c, which may lead to remote code execution in certain Python applications that accept floating-point numbers as untrusted input, as demonstrated by a 1e300 argument to c_double.from_param. This occurs because sprintf is used unsafely.
CVE-2021-3733	6.5 (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H)	There's a flaw in urllib's AbstractBasicAuthHandler class. An attacker who controls a malicious HTTP server that an HTTP client (such as web browser) connects to, could trigger a Regular Expression Denial of Service (ReDOS) during an authentication request with a specially crafted payload that is sent by the server to the client. The greatest threat that this flaw poses is to application availability.
CVE-2021-3737	7.5 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H)	A flaw was found in python. An improperly handled HTTP response in the HTTP client code of python may allow a remote attacker, who controls the HTTP server, to make the client script enter an infinite loop, consuming CPU time. The highest threat from this vulnerability is to system availability.
CVE-2021-4189	5.3 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N)	A flaw was found in Python, specifically in the FTP (File Transfer Protocol) client library in PASV (passive) mode. The issue is how the FTP client trusts the host from the PASV response by default. This flaw allows an attacker to set up a malicious FTP server that can trick FTP clients into connecting back to a given IP address and port. This vulnerability could lead to FTP client scanning ports, which otherwise would not have been possible.
CVE-2022-45061	7.5 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H)	An issue was discovered in Python before 3.11.1. An unnecessary quadratic algorithm exists in one path when processing some inputs to the IDNA (RFC 3490) decoder, such that a crafted, unreasonably long name being presented to the decoder could lead to a CPU denial of service. Hostnames are often supplied by remote servers that could be controlled by a malicious actor; in such a scenario, they could trigger excessive CPU consumption on the client attempting to make use of an attacker-supplied supposed hostname. For example, the attack payload could be placed in the Location header of an HTTP response with status code 302. A fix is planned in 3.11.1, 3.10.9, 3.9.16, 3.8.16, and 3.7.16.

Juniper SIRT is not aware of any malicious exploitation of this vulnerability.

This issue was discovered by a third-party upstream provider.

Solution

The following software releases have been updated to resolve this specific issue: Policy Enforcer 24.1R3 and all subsequent releases.

This issue is being tracked as 1653070 which is visible on the Customer Support website.

Note: Juniper SIRT's policy is not to evaluate releases which are beyond End of Engineering (EOE) or End of Life (EOL).

Workaround

There are no known workarounds for these issues.

Severity Assessment

Information for how Juniper Networks uses CVSS can be found at KB 16446 [juniper.net] "Common Vulnerability Scoring System (CVSS) and Juniper's Security Advisories."

Modification History