What is CVE-2021-27345?

CVE-2021-27345 is a medium-severity vulnerability in Long Range Zip Project, classified under NULL Pointer Dereference. CVSS score: 5.5/10. Published 2021-06-10.

How severe is CVE-2021-27345?

Medium severity. CVSS v3 base score is 5.5 out of 10.

Is CVE-2021-27345 known to be exploited?

3 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.

NULL pointer dereference in Long Range Zip Project

CVE-2021-27345

A null pointer dereference was discovered in ucompthread in stream.c in Irzip 0.631 which allows attackers to cause a denial of service (DOS) via a crafted compressed file.

Published 2021-06-10 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 5.5 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.007 (51.9th percentile), scored 2026-10-01.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 52nd percentile — 51.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.007 · newest: 0.007 · change: 0.000

Affected products

Long Range Zip Project — versions 0.631
Debian Linux — versions 9.0

Weakness classification (CWE)

CWE-476 — NULL Pointer Dereference

Public proof-of-concept exploits

References

github.com/ckolivas/lrzip/issues/164 (Exploit, Patch, Third Party Advisory, Issue Tracking)
lists.debian.org/debian-lts-announce/2022/04/msg00012.html (mailing-list, Mailing List, Third Party Advisory)

Frequently asked questions

What is CVE-2021-27345?: CVE-2021-27345 is a medium-severity vulnerability in Long Range Zip Project, classified under NULL Pointer Dereference. CVSS score: 5.5/10. Published 2021-06-10.
How severe is CVE-2021-27345?: Medium severity. CVSS v3 base score is 5.5 out of 10.
Is CVE-2021-27345 known to be exploited?: 3 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.