What is CVE-2018-21035?

CVE-2018-21035 is a high-severity vulnerability in Qt, classified under Allocation of Resources Without Limits or Throttling. CVSS score: 7.5/10. Published 2020-02-28.

How severe is CVE-2018-21035?

High severity. CVSS v3 base score is 7.5 out of 10.

Is CVE-2018-21035 known to be exploited?

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

Resource exhaustion in Qt

CVE-2018-21035

In Qt through 5.14.1, the WebSocket implementation accepts up to 2GB for frames and 2GB for messages. Smaller limits cannot be configured. This makes it easier for attackers to cause a denial of service (memory consumption).

EPSS: 0.023 (81.8th 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

Qt
N/a — versions n/a

Weakness classification (CWE)

CWE-770 — Allocation of Resources Without Limits or Throttling

Public proof-of-concept exploits

PalindromeLabs/awesome-websocket-security

References

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

Frequently asked questions

What is CVE-2018-21035?: CVE-2018-21035 is a high-severity vulnerability in Qt, classified under Allocation of Resources Without Limits or Throttling. CVSS score: 7.5/10. Published 2020-02-28.
How severe is CVE-2018-21035?: High severity. CVSS v3 base score is 7.5 out of 10.
Is CVE-2018-21035 known to be exploited?: 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.