Out-of-bounds Read in Haxx Libcurl
CVE-2018-1000005
libcurl 7.49.0 to and including 7.57.0 contains an out bounds read in code handling HTTP/2 trailers. It was reported (https://github.com/curl/curl/pull/2231) that reading an HTTP/2 trailer could mess up future trailers since the stored size was one byte less than required. The problem is that the code that creates HTTP/1-like headers from the HTTP/2 trailer data once appended a string like `:` to the target buffer, while this was recently changed to `: ` (a space was added after the colon) but the following math wasn't updated correspondingly. When accessed, the data is read out of bounds and causes either a crash or that the (too large) data gets passed to client write. This could lead to a denial-of-service situation or an information disclosure if someone has a service that echoes back or uses the trailers for something.
Vulnerability class: Buffer Overflow
Published · last modified .
CVSS v3 metric
CVSS v3 base score 9.1 (Critical). Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H.
EPSS exploit prediction
EPSS: 0.046 (91.5th percentile), scored .
Low probability of exploitation in the next 30 days, but still tracked. 91st percentile — 91.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.046 · newest: 0.046 · change: 0.000
Affected products
- Haxx Libcurl
- Canonical Ubuntu Linux — versions 14.04, 16.04, 17.10
- Debian Linux — versions 8.0, 9.0
Weakness classification (CWE)
References
- www.securitytracker.com/id/1040273 (VDB Entry, Third Party Advisory, vdb-entry)
- usn.ubuntu.com/3554-1/ (vendor-advisory, Third Party Advisory)
- www.debian.org/security/2018/dsa-4098 (vendor-advisory, Third Party Advisory)
- curl.haxx.se/docs/adv_2018-824a.html (Patch, Vendor Advisory)
- github.com/curl/curl/pull/2231 (Patch, Third Party Advisory, Issue Tracking)
- access.redhat.com/errata/RHSA-2019:1543 (vendor-advisory)
Frequently asked questions
- What is CVE-2018-1000005?
- CVE-2018-1000005 is a critical-severity vulnerability in Haxx Libcurl, classified under Out-of-bounds Read. CVSS score: 9.1/10. Published 2018-01-24.
- How severe is CVE-2018-1000005?
- Critical severity. CVSS v3 base score is 9.1 out of 10.