CVE-2021-33026

Flask Caching vulnerability

CVSS

9.8

EPSS

7.3%

EPSS pct

94th

Exploited

No known

The Flask-Caching extension through 1.10.1 for Flask relies on Pickle for serialization, which may lead to remote code execution or local privilege escalation. If an attacker gains access to cache storage (e.g., filesystem, Memcached, Redis, etc.), they can construct a crafted payload, poison the cache, and execute Python code. NOTE: a third party indicates that exploitation is extremely unlikely unless the machine is already compromised; in other cases, the attacker would be unable to write their payload to the cache and generate the required collision

Affected vendor

Flask Caching Project

Affected product

Flask Caching

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Weakness type (CWE)

CWE-502 — Deserialization of Untrusted Data

Published

2021-05-13

Risk analysis

Based on its CVSS vector, this vulnerability is exploitable over the network, low attack complexity, requiring no privileges, no user interaction. Successful exploitation leads to high impact to confidentiality, high impact to integrity, high impact to availability.

Its EPSS score of 7.3% reflects a lower probability of exploitation activity in the wild over the next 30 days, placing it above 94% of all scored CVEs.

Check your external exposure to CVE-2021-33026

Confirm whether Flask Caching Project Flask Caching is running on any internet-facing host or subdomain.
Match discovered service fingerprints against the version affected by CVE-2021-33026.
Prioritise remediation if the asset is public, business-critical, or near authentication/payment flows.

How ThreatPort helps with CVE-2021-33026

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