PyJWT up to 1.5.0 PEM Encoded Public Key symmetric/asymmetric invalid_strings access control

CVSS Meta Temp Score
CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.
Current Exploit Price (≈)
Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.
CTI Interest Score
Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
6.9$0-$5k0.00

Summaryinfo

A vulnerability identified as critical has been detected in PyJWT up to 1.5.0. Affected is the function invalid_strings of the file symmetric/asymmetric of the component PEM Encoded Public Key Handler. This manipulation causes access control. The identification of this vulnerability is CVE-2017-11424. It is possible to initiate the attack remotely. There is no exploit available. You should upgrade the affected component.

Detailsinfo

A vulnerability has been found in PyJWT up to 1.5.0 and classified as critical. Affected by this vulnerability is the function invalid_strings of the file symmetric/asymmetric of the component PEM Encoded Public Key Handler. The manipulation with an unknown input leads to a access control vulnerability. The CWE definition for the vulnerability is CWE-284. The product does not restrict or incorrectly restricts access to a resource from an unauthorized actor. As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:

In PyJWT 1.5.0 and below the `invalid_strings` check in `HMACAlgorithm.prepare_key` does not account for all PEM encoded public keys. Specifically, the PKCS1 PEM encoded format would be allowed because it is prefaced with the string `-----BEGIN RSA PUBLIC KEY-----` which is not accounted for. This enables symmetric/asymmetric key confusion attacks against users using the PKCS1 PEM encoded public keys, which would allow an attacker to craft JWTs from scratch.

The bug was discovered 07/18/2017. The weakness was shared 08/24/2017 (GitHub Repository). The advisory is shared at github.com. This vulnerability is known as CVE-2017-11424 since 07/18/2017. The attack can be launched remotely. The exploitation doesn't need any form of authentication. Technical details are known, but no exploit is available. MITRE ATT&CK project uses the attack technique T1068 for this issue.

The vulnerability was handled as a non-public zero-day exploit for at least 37 days. During that time the estimated underground price was around $0-$5k. The vulnerability scanner Nessus provides a plugin with the ID 103331 (Debian DSA-3979-1 : pyjwt - security update), which helps to determine the existence of the flaw in a target environment. It is assigned to the family Debian Local Security Checks and running in the context l. The commercial vulnerability scanner Qualys is able to test this issue with plugin 276895 (Fedora Security Update for python-jwt (FEDORA-2017-b9f07dfaca)).

Upgrading eliminates this vulnerability. A possible mitigation has been published 4 weeks after the disclosure of the vulnerability.

The vulnerability is also documented in the vulnerability database at Tenable (103331). If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Productinfo

Name

Version

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 7.4
VulDB Meta Temp Score: 6.9

VulDB Base Score: 7.3
VulDB Temp Score: 6.4
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 7.5
NVD Vector: 🔍

CVSSv2info

AVACAuCIA
💳💳💳💳💳💳
💳💳💳💳💳💳
💳💳💳💳💳💳
VectorComplexityAuthenticationConfidentialityIntegrityAvailability
UnlockUnlockUnlockUnlockUnlockUnlock
UnlockUnlockUnlockUnlockUnlockUnlock
UnlockUnlockUnlockUnlockUnlockUnlock

VulDB Base Score: 🔍
VulDB Temp Score: 🔍
VulDB Reliability: 🔍

NVD Base Score: 🔍

Exploitinginfo

Class: Access control
CWE: CWE-284 / CWE-266
CAPEC: 🔍
ATT&CK: 🔍

Physical: No
Local: No
Remote: Yes

Availability: 🔍
Status: Not defined

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

0-DayUnlockUnlockUnlockUnlock
TodayUnlockUnlockUnlockUnlock

Nessus ID: 103331
Nessus Name: Debian DSA-3979-1 : pyjwt - security update
Nessus File: 🔍
Nessus Risk: 🔍
Nessus Family: 🔍
Nessus Context: 🔍

OpenVAS ID: 53377
OpenVAS Name: Debian Security Advisory DSA 3979-1 (pyjwt - security update)
OpenVAS File: 🔍
OpenVAS Family: 🔍

Qualys ID: 🔍
Qualys Name: 🔍

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

Reaction Time: 🔍
0-Day Time: 🔍
Exposure Time: 🔍

Patch: github.com

Timelineinfo

07/18/2017 🔍
07/18/2017 +0 days 🔍
08/24/2017 +37 days 🔍
08/24/2017 +0 days 🔍
08/25/2017 +1 days 🔍
09/19/2017 +25 days 🔍
09/20/2017 +1 days 🔍
12/16/2022 +1913 days 🔍

Sourcesinfo

Advisory: github.com
Status: Not defined
Confirmation: 🔍

CVE: CVE-2017-11424 (🔍)
GCVE (CVE): GCVE-0-2017-11424
GCVE (VulDB): GCVE-100-105709

OVAL: 🔍

Entryinfo

Created: 08/25/2017 08:45
Updated: 12/16/2022 14:38
Changes: 08/25/2017 08:45 (68), 11/10/2019 08:32 (10), 12/16/2022 14:38 (4)
Complete: 🔍
Cache ID: 216::103

If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Discussion

No comments yet. Languages: en.

Please log in to comment.

◂ PreviousOverviewNext ▸

Do you want to use VulDB in your project?

Use the official API to access entries easily!