CVE-2019-20788 — libvncclient/cursor

libvncclient/cursor.c in LibVNCServer through 0.9.12 has a HandleCursorShape integer overflow and heap-based buffer overflow via a large height or width value. NOTE: this may overlap CVE-2019-15690.

01What is this vulnerability?

libvncclient/cursor.c in LibVNCServer through 0.9.12 has a HandleCursorShape integer overflow and heap-based buffer overflow via a large height or width value. NOTE: this may overlap CVE-2019-15690.

02Affected products

Vendor	Product	Versions
n	a / n/a	n/a

03Active exploitation status

Not currently listed on the CISA Known Exploited Vulnerabilities (KEV) catalog. EPSS is the best forward-looking signal — see the EPSS row above.

04Recommended remediation

• Patch to a fixed version listed in the vendor advisory (see references below).
• Mitigate with WAF rules, network egress filters, or feature flags where the patch is not yet available.
• Hunt historical logs for exploitation indicators — see Detection signatures below.

05Technical details

For the full vendor write-up, exploit chains, and reference implementations, see the references list in section 09.

06Detection signatures

Ask SARA in chat to draft a starting detection for this CVE in your stack of choice.

07Related CVEs

08Timeline

• Published: 2020-04-23T18:06:55.000Z
• Last modified: 2024-08-05T02:53:09.241Z

09References

• github.com — https://github.com/LibVNC/libvncserver/commit/54220248886b5001fbbb9fa73c4e1a2cb9…
• lists.opensuse.org — http://lists.opensuse.org/opensuse-security-announce/2020-05/msg00027.html
• usn.ubuntu.com — https://usn.ubuntu.com/4407-1/
• securitylab.github.com — https://securitylab.github.com/advisories/GHSL-2020-064-libvnc-libvncclient
• cert-portal.siemens.com — https://cert-portal.siemens.com/productcert/pdf/ssa-390195.pdf