CVE-2018-1000005
Publication date 24 January 2018
Last updated 25 August 2025
Ubuntu priority
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.
From the Ubuntu Security Team
leosilva> vulnerability code was introduced after version 7.47 leosilva> trusty and precise/esm are not-affected.
Status
| Package | Ubuntu Release | Status |
|---|---|---|
| curl | ||
| 16.04 LTS xenial |
Fixed 7.47.0-1ubuntu2.6
|
|
| 14.04 LTS trusty |
Not affected
|
Severity score breakdown
| Parameter | Value |
|---|---|
| Base score |
9.1 · Critical
|
| Attack vector | Network |
| Attack complexity | Low |
| Privileges required | None |
| User interaction | None |
| Scope | Unchanged |
| Confidentiality | High |
| Integrity impact | None |
| Availability impact | High |
| Vector | CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H |
References
Related Ubuntu Security Notices (USN)
- USN-3554-1
- curl vulnerabilities
- 31 January 2018