7.5
HIGH
CVE-2021-40839
Apache Reencode Infinite Typecode Decoding Vulnerability
Description

The rencode package through 1.0.6 for Python allows an infinite loop in typecode decoding (such as via ;\x2f\x7f), enabling a remote attack that consumes CPU and memory.

INFO

Published Date :

Sept. 10, 2021, 2:15 a.m.

Last Modified :

Nov. 7, 2023, 3:38 a.m.

Remotely Exploitable :

Yes !

Impact Score :

3.6

Exploitability Score :

3.9
Public PoC/Exploit Available at Github

CVE-2021-40839 has a 2 public PoC/Exploit available at Github. Go to the Public Exploits tab to see the list.

Affected Products

The following products are affected by CVE-2021-40839 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Fedoraproject fedora
1 Rencode_project rencode

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

None

Updated: 3 months, 1 week ago
8 stars 1 fork 1 watcher
Born at : June 21, 2022, 7:45 a.m. This repo has been linked 943 different CVEs too.

Dirty Cow kernel exploit without libcrypt dependency

C

Updated: 2 years, 8 months ago
1 stars 0 fork 0 watcher
Born at : Dec. 13, 2021, 9:47 a.m. This repo has been linked 1 different CVEs too.

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2021-40839 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2021-40839 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • CVE Modified by [email protected]

    May. 14, 2024

    Action Type Old Value New Value
  • CVE Modified by [email protected]

    Nov. 07, 2023

    Action Type Old Value New Value
    Added Reference MITRE https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/BMVQRPDVSVZNGGX57CFKCYT3DEYO4QB6/ [No types assigned]
    Added Reference MITRE https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/MCLETLGVM5DBX6QNHQFW6TWGO5T3DENY/ [No types assigned]
    Removed Reference MITRE https://lists.fedoraproject.org/archives/list/[email protected]/message/BMVQRPDVSVZNGGX57CFKCYT3DEYO4QB6/
    Removed Reference MITRE https://lists.fedoraproject.org/archives/list/[email protected]/message/MCLETLGVM5DBX6QNHQFW6TWGO5T3DENY/
  • Modified Analysis by [email protected]

    Feb. 22, 2022

    Action Type Old Value New Value
    Changed Reference Type https://lists.fedoraproject.org/archives/list/[email protected]/message/BMVQRPDVSVZNGGX57CFKCYT3DEYO4QB6/ No Types Assigned https://lists.fedoraproject.org/archives/list/[email protected]/message/BMVQRPDVSVZNGGX57CFKCYT3DEYO4QB6/ Mailing List, Third Party Advisory
    Changed Reference Type https://lists.fedoraproject.org/archives/list/[email protected]/message/MCLETLGVM5DBX6QNHQFW6TWGO5T3DENY/ No Types Assigned https://lists.fedoraproject.org/archives/list/[email protected]/message/MCLETLGVM5DBX6QNHQFW6TWGO5T3DENY/ Mailing List, Third Party Advisory
    Added CPE Configuration OR *cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:* *cpe:2.3:o:fedoraproject:fedora:35:*:*:*:*:*:*:*
  • CVE Modified by [email protected]

    Feb. 15, 2022

    Action Type Old Value New Value
    Added Reference https://lists.fedoraproject.org/archives/list/[email protected]/message/MCLETLGVM5DBX6QNHQFW6TWGO5T3DENY/ [No Types Assigned]
  • CVE Modified by [email protected]

    Feb. 15, 2022

    Action Type Old Value New Value
    Added Reference https://lists.fedoraproject.org/archives/list/[email protected]/message/BMVQRPDVSVZNGGX57CFKCYT3DEYO4QB6/ [No Types Assigned]
  • Modified Analysis by [email protected]

    Dec. 02, 2021

    Action Type Old Value New Value
    Changed Reference Type https://security.netapp.com/advisory/ntap-20211008-0001/ No Types Assigned https://security.netapp.com/advisory/ntap-20211008-0001/ Third Party Advisory
  • CVE Modified by [email protected]

    Oct. 08, 2021

    Action Type Old Value New Value
    Added Reference https://security.netapp.com/advisory/ntap-20211008-0001/ [No Types Assigned]
  • Initial Analysis by [email protected]

    Sep. 23, 2021

    Action Type Old Value New Value
    Added CVSS V2 NIST (AV:N/AC:L/Au:N/C:N/I:N/A:P)
    Added CVSS V3.1 NIST AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
    Changed Reference Type https://github.com/aresch/rencode/commit/572ff74586d9b1daab904c6f7f7009ce0143bb75 No Types Assigned https://github.com/aresch/rencode/commit/572ff74586d9b1daab904c6f7f7009ce0143bb75 Patch, Third Party Advisory
    Changed Reference Type https://github.com/aresch/rencode/pull/29 No Types Assigned https://github.com/aresch/rencode/pull/29 Patch, Third Party Advisory
    Changed Reference Type https://pypi.org/project/rencode/#history No Types Assigned https://pypi.org/project/rencode/#history Third Party Advisory
    Changed Reference Type https://seclists.org/fulldisclosure/2021/Sep/16 No Types Assigned https://seclists.org/fulldisclosure/2021/Sep/16 Mailing List, Third Party Advisory
    Added CWE NIST CWE-835
    Added CPE Configuration OR *cpe:2.3:a:rencode_project:rencode:*:*:*:*:*:python:*:* versions up to (including) 1.0.6
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2021-40839 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2021-40839 weaknesses.

Exploit Prediction

EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days.

0.43 }} 0.03%

score

0.74517

percentile

CVSS31 - Vulnerability Scoring System
Attack Vector
Attack Complexity
Privileges Required
User Interaction
Scope
Confidentiality
Integrity
Availability