Use After Free in Haxx Curl
CVE-2018-16840
A heap use-after-free flaw was found in curl versions from 7.59.0 through 7.61.1 in the code related to closing an easy handle. When closing and cleaning up an 'easy' handle in the `Curl_close()` function, the library code first frees a struct (without nulling the pointer) and might then subsequently erroneously write to a struct field within that already freed struct.
Vulnerability class: Use-After-Free
Published · last modified .
CVSS v3 metric
CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.034 (88.4th percentile), scored .
Low probability of exploitation in the next 30 days, but still tracked. 88th percentile — 88.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.034 · newest: 0.034 · change: 0.000
Affected products
- Haxx Curl
- The Curl Project — versions from 7.59.0 to 7.61.1
- Canonical Ubuntu Linux — versions 14.04, 16.04, 18.04
Weakness classification (CWE)
Public proof-of-concept exploits
References
- security.gentoo.org/glsa/201903-03 (vendor-advisory, Third Party Advisory)
- bugzilla.redhat.com/show_bug.cgi (Third Party Advisory, Issue Tracking)
- github.com/curl/curl/commit/81d135d67155c5295b1033679c606165d4e28f3f (Patch, Third Party Advisory)
- www.securitytracker.com/id/1042013 (VDB Entry, Third Party Advisory, vdb-entry)
- curl.haxx.se/docs/CVE-2018-16840.html (Patch, Vendor Advisory)
- usn.ubuntu.com/3805-1/ (vendor-advisory, Third Party Advisory)
Frequently asked questions
- What is CVE-2018-16840?
- CVE-2018-16840 is a critical-severity vulnerability in Haxx Curl, classified under Use After Free. CVSS score: 9.8/10. Published 2018-10-31.
- How severe is CVE-2018-16840?
- Critical severity. CVSS v3 base score is 9.8 out of 10.
- Is CVE-2018-16840 known to be exploited?
- 7 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.