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Vulnerability · Published Sep 10, 2021 · Assigned by mitre

CVE-2021-40839

High 7.5

In plain English

A high-severity security flaw in the py3-rencode package (Alpine). There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 5.5% (higher than 93% of all known vulnerabilities). Ready-made attack tooling exists: public proof-of-concept code. Fixed versions are available - upgrade the affected package.

Severity (CVSS NVD)7.5High
Exploit odds (30 days)5.5%top 7.2% of all CVEs
Exploited in the wildNo reportsnot in CISA KEV
Attack tooling1Public PoC

Official 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.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Alpine:v3.20py3-rencode1.0.6-r7ALPINE-CVE-2021-40839
Alpine:v3.21py3-rencode1.0.6-r7ALPINE-CVE-2021-40839
Alpine:v3.22py3-rencode1.0.6-r7ALPINE-CVE-2021-40839
Alpine:v3.23py3-rencode1.0.6-r7ALPINE-CVE-2021-40839
Alpine:v3.24py3-rencode1.0.6-r7ALPINE-CVE-2021-40839
Debian:12python-rencode1.0.6-2DEBIAN-CVE-2021-40839
Debian:13python-rencode1.0.6-2DEBIAN-CVE-2021-40839
Debian:14python-rencode1.0.6-2DEBIAN-CVE-2021-40839
PyPIrencodeno fix listedGHSA-gh8j-2pgf-x458
PyPIrencodeno fix listedPYSEC-2021-345
Ubuntu:22.04:LTSpython-rencodeno fix listedUBUNTU-CVE-2021-40839

Affected products (as reported)

VendorProductVersions
n/a n/a n/a

References