CVE-2018-6390 — The WStr::assign function in kso

The WStr::assign function in kso.dll in Kingsoft WPS Office 10.1.0.7106 and 10.2.0.5978 does not validate the size of the source memory block before an _copy call, which allows remote attackers to cause a denial of service (access violation and application crash) via a crafted (a

01What is this vulnerability?

The WStr::assign function in kso.dll in Kingsoft WPS Office 10.1.0.7106 and 10.2.0.5978 does not validate the size of the source memory block before an _copy call, which allows remote attackers to cause a denial of service (access violation and application crash) via a crafted (a) web page, (b) office document, or (c) .rtf file.

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

No directly-cited follow-up CVEs in the KB record for this advisory. The references list in section 09 carries the vendor cross-references.

08Timeline

• Published: 2018-01-29T19:00:00.000Z
• Last modified: 2024-09-17T03:42:45.869Z

09References

• github.com — https://github.com/Khwarezmia/WPS_POC/tree/master/wps_20180129