Lua 5.3.5 lapi.c lua_upvaluejoin Argument use after free

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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.
6.1	$0-$5k	0.00

Summaryinfo

A vulnerability classified as problematic was found in Lua 5.3.5. Affected is the function lua_upvaluejoin of the file lapi.c. Executing a manipulation as part of Argument can lead to use after free. This vulnerability appears as CVE-2019-6706. The attack may be performed from remote. In addition, an exploit is available. Upgrading the affected component is advised.

Detailsinfo

A vulnerability was found in Lua 5.3.5. It has been declared as problematic. This vulnerability affects the function lua_upvaluejoin of the file lapi.c. The manipulation as part of a Argument leads to a use after free vulnerability. The CWE definition for the vulnerability is CWE-416. Referencing memory after it has been freed can cause a program to crash, use unexpected values, or execute code. As an impact it is known to affect availability. CVE summarizes:

Lua 5.3.5 has a use-after-free in lua_upvaluejoin in lapi.c. For example, a crash outcome might be achieved by an attacker who is able to trigger a debug.upvaluejoin call in which the arguments have certain relationships.

The bug was discovered 01/10/2019. The weakness was presented 01/23/2019 (Website). The advisory is shared for download at lua.2524044.n2.nabble.com. This vulnerability was named CVE-2019-6706 since 01/23/2019. The exploitation appears to be easy. The attack can be initiated remotely. No form of authentication is required for a successful exploitation. Technical details and also a public exploit are known.

It is possible to download the exploit at exploit-db.com. It is declared as proof-of-concept. The vulnerability was handled as a non-public zero-day exploit for at least 13 days. During that time the estimated underground price was around $0-$5k. The vulnerability scanner Nessus provides a plugin with the ID 121446 (Fedora 29 : lua (2019-ee57bda7ae)), which helps to determine the existence of the flaw in a target environment. It is assigned to the family Fedora Local Security Checks and running in the context l. The commercial vulnerability scanner Qualys is able to test this issue with plugin 197423 (Ubuntu Security Notification for Lua Vulnerability(USN-3941-1)).

Upgrading eliminates this vulnerability. A possible mitigation has been published 1 weeks after the disclosure of the vulnerability.

The vulnerability is also documented in the databases at Exploit-DB (46246) and Tenable (121446). Once again VulDB remains the best source for vulnerability data.

Productinfo

Name

Version

5.3.5

License

open-source

Website

Product: https://github.com/lua/lua/

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 6.4
VulDB Meta Temp Score: 6.1

VulDB Base Score: 5.3
VulDB Temp Score: 4.8
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 7.5
NVD Vector: 🔍

CVSSv2info

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VulDB Base Score: 🔍
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NVD Base Score: 🔍

Exploitinginfo

Class: Use after free
CWE: CWE-416 / CWE-119
CAPEC: 🔍
ATT&CK: 🔍

Physical: No
Local: No
Remote: Yes

Availability: 🔍
Access: Public
Status: Proof-of-Concept
Download: 🔍

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

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Nessus ID: 121446
Nessus Name: Fedora 29 : lua (2019-ee57bda7ae)
Nessus File: 🔍
Nessus Risk: 🔍
Nessus Family: 🔍
Nessus Context: 🔍

Qualys ID: 🔍
Qualys Name: 🔍

Exploit-DB: 🔍

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

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

Patch: github.com

Timelineinfo

01/10/2019 🔍
01/23/2019 +13 days 🔍
01/23/2019 +0 days 🔍
01/23/2019 +0 days 🔍
01/24/2019 +1 days 🔍
01/30/2019 +6 days 🔍
01/30/2019 +0 days 🔍
02/02/2025 +2195 days 🔍