CVE-2018-1000005

MEDIUM

Description

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.

References

http://www.securitytracker.com/id/1040273

https://access.redhat.com/errata/RHSA-2019:1543

https://curl.haxx.se/docs/adv_2018-824a.html

https://github.com/curl/curl/pull/2231

https://usn.ubuntu.com/3554-1/

https://www.debian.org/security/2018/dsa-4098

Details

Source: MITRE

Published: 2018-01-24

Updated: 2019-06-18

Type: CWE-125

Risk Information

CVSS v2.0

Base Score: 6.4

Vector: AV:N/AC:L/Au:N/C:P/I:N/A:P

Impact Score: 4.9

Exploitability Score: 10

Severity: MEDIUM

CVSS v3.0

Base Score: 9.1

Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H

Impact Score: 5.2

Exploitability Score: 3.9

Severity: CRITICAL