What is CVE-2021-39520?

CVE-2021-39520 is a medium-severity vulnerability in Jpeg Libjpeg, classified under NULL Pointer Dereference. CVSS score: 6.5/10. Published 2021-09-20.

How severe is CVE-2021-39520?

Medium severity. CVSS v3 base score is 6.5 out of 10.

Is CVE-2021-39520 known to be exploited?

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

NULL pointer dereference in Jpeg Libjpeg

CVE-2021-39520

An issue was discovered in libjpeg through 2020021. A NULL pointer dereference exists in the function BlockBitmapRequester::PushReconstructedData() located in blockbitmaprequester.cpp. It allows an attacker to cause Denial of Service.

EPSS: 0.009 (55.0th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H.

Affected products

Jpeg Libjpeg
N/a — versions n/a

Weakness classification (CWE)

CWE-476 — NULL Pointer Dereference

Public proof-of-concept exploits

seviezhou/Kraken

References

cve@mitre.org (Exploit, Patch, Third Party Advisory, x_refsource_MISC, Issue Tracking)

Frequently asked questions

What is CVE-2021-39520?: CVE-2021-39520 is a medium-severity vulnerability in Jpeg Libjpeg, classified under NULL Pointer Dereference. CVSS score: 6.5/10. Published 2021-09-20.
How severe is CVE-2021-39520?: Medium severity. CVSS v3 base score is 6.5 out of 10.
Is CVE-2021-39520 known to be exploited?: 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.