Python up to 3.8.3 TAR Archive Lib/tarfile.py _proc_pax infinite loop

CVSS Meta Temp Score
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CTI Interest Score
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6.4$0-$5k0.00

Summaryinfo

A vulnerability marked as problematic has been reported in Python up to 3.8.3. Affected by this vulnerability is the function _proc_pax in the library Lib/tarfile.py of the component TAR Archive Handler. This manipulation causes infinite loop. This vulnerability is handled as CVE-2019-20907. The attack can be initiated remotely. There is not any exploit available.

Detailsinfo

A vulnerability classified as problematic was found in Python up to 3.8.3 (Programming Language Software). Affected by this vulnerability is the function _proc_pax in the library Lib/tarfile.py of the component TAR Archive Handler. The manipulation with an unknown input leads to a infinite loop vulnerability. The CWE definition for the vulnerability is CWE-835. The product contains an iteration or loop with an exit condition that cannot be reached, i.e., an infinite loop. As an impact it is known to affect availability. The summary by CVE is:

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.

The weakness was released 07/13/2020 (Website). The advisory is shared at bugs.python.org. This vulnerability is known as CVE-2019-20907 since 07/13/2020. The exploitation appears to be easy. 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 T1499 for this issue.

The vulnerability scanner Nessus provides a plugin with the ID 234998 (Amazon Linux AMI : python26 (ALAS-2025-1972)), which helps to determine the existence of the flaw in a target environment.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

The vulnerability is also documented in the vulnerability database at Tenable (234998). If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Productinfo

Type

Name

Version

License

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

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

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

NVD Base Score: 7.5
NVD Vector: 🔍

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔍
VulDB Temp Score: 🔍
VulDB Reliability: 🔍

NVD Base Score: 🔍

Exploitinginfo

Class: Infinite loop
CWE: CWE-835 / CWE-404
CAPEC: 🔍
ATT&CK: 🔍

Physical: No
Local: No
Remote: Yes

Availability: 🔍
Status: Not defined

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

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Nessus ID: 234998
Nessus Name: Amazon Linux AMI : python26 (ALAS-2025-1972)

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: no mitigation known
Status: 🔍

0-Day Time: 🔍

Timelineinfo

07/13/2020 🔍
07/13/2020 +0 days 🔍
07/14/2020 +1 days 🔍
04/30/2025 +1751 days 🔍

Sourcesinfo

Advisory: bugs.python.org
Status: Not defined
Confirmation: 🔍

CVE: CVE-2019-20907 (🔍)
GCVE (CVE): GCVE-0-2019-20907
GCVE (VulDB): GCVE-100-157861

Entryinfo

Created: 07/14/2020 07:09
Updated: 04/30/2025 13:13
Changes: 07/14/2020 07:09 (38), 07/14/2020 07:14 (18), 10/29/2020 12:51 (1), 04/30/2025 13:13 (18)
Complete: 🔍
Cache ID: 216::103

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

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