CVE-2018-1000005 Information

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.

CVSS Vector

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

Reference

http://www.securitytracker.com/id/1040273 https://access.redhat.com/errata/RHSA-2019:1543 https://curl.haxx.se/docs/adv_2018-824a.html https://curl.haxx.se/docs/adv_2018-824a.html https://github.com/curl/curl/pull/2231 https://github.com/curl/curl/pull/2231 https://usn.ubuntu.com/3554-1/ https://www.debian.org/security/2018/dsa-4098 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. cpe:2.3:a:haxx:libcurl::::::::

Attack Complexity

LOW

Privileges Required

NONE

User Interaction Required

NONE

Scope

NONE

Confidentiality Impact

UNCHANGED

Integrity Impact

HIGH

Availability Impact

NONE

Base Score

HIGH

Base Severity

9.1