Resource exhaustion in Caronc Apprise

CVE-2021-39229

Apprise is an open source library which allows you to send a notification to almost all of the most popular notification services available. In affected versions users who use Apprise granting them access to the IFTTT plugin (which just comes out of the box) are subject to a denial of service attack on an inefficient regular expression. The vulnerable regular expression is [here](https://github.com/caronc/apprise/blob/0007eade20934ddef0aba38b8f1aad980cfff253/apprise/plugins/NotifyIFTTT.py#L356-L359). The problem has been patched in release version 0.9.5.1. Users who are unable to upgrade are advised to remove `apprise/plugins/NotifyIFTTT.py` to eliminate the service.

Vulnerability class: DoS (Denial of Service)

EPSS: 0.019 (78.0th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2021-39229?
CVE-2021-39229 is a high-severity vulnerability in Caronc Apprise, classified under Uncontrolled Resource Consumption. CVSS score: 7.5/10. Published 2021-09-20.
How severe is CVE-2021-39229?
High severity. CVSS v3 base score is 7.5 out of 10.
Is CVE-2021-39229 known to be exploited?
1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.