CVE-2018-20819 — io/ZlibCompression

io/ZlibCompression.cc in the decompression component in Dropbox Lepton 1.2.1 allows attackers to cause a denial of service (heap-based buffer overflow and application crash) or possibly have unspecified other impact by crafting a jpg image file. The root cause is a missing check

01What is this vulnerability?

io/ZlibCompression.cc in the decompression component in Dropbox Lepton 1.2.1 allows attackers to cause a denial of service (heap-based buffer overflow and application crash) or possibly have unspecified other impact by crafting a jpg image file. The root cause is a missing check of header payloads that may be (incorrectly) larger than the maximum file size.

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: 2019-04-23T13:53:36.000Z
• Last modified: 2024-08-05T12:12:27.304Z

09References

• github.com — https://github.com/dropbox/lepton/issues/112