CVE-2018-1000005: canonical ubuntu_linux Out-of-bounds Read

Vulnerability summary

CVE-2018-1000005 is a critical (CVSS 9.1) Out-of-bounds Read vulnerability in canonical ubuntu_linux. EPSS estimates a 4.56% chance of exploitation in the next 30 days, higher than 91.4% of scored vulnerabilities.

Timeline

1. 24-01-2018
   PublishedVulnerability first disclosed.
2. 05-08-2024
   Last modifiedVulnerability information updated.

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.

• CWE-125Out-of-bounds ReadThe product reads data past the end, or before the beginning, of the intended buffer.