CVE-2017-7805

Publication date 29 September 2017

Last updated 25 August 2025

Ubuntu priority

Medium

Why this priority?

Cvss 3 Severity Score

7.5 · High

Score breakdown

Description

During TLS 1.2 exchanges, handshake hashes are generated which point to a message buffer. This saved data is used for later messages but in some cases, the handshake transcript can exceed the space available in the current buffer, causing the allocation of a new buffer. This leaves a pointer pointing to the old, freed buffer, resulting in a use-after-free when handshake hashes are then calculated afterwards. This can result in a potentially exploitable crash. This vulnerability affects Firefox < 56, Firefox ESR < 52.4, and Thunderbird < 52.4.

Status

Package Ubuntu Release Status
firefox 18.10 cosmic
Fixed 56.0+build6-0ubuntu1
18.04 LTS bionic
Fixed 56.0+build6-0ubuntu1
17.10 artful
Fixed 56.0+build6-0ubuntu1
17.04 zesty
Fixed 56.0+build6-0ubuntu0.17.04.1
16.04 LTS xenial
Fixed 56.0+build6-0ubuntu0.16.04.1
14.04 LTS trusty
Fixed 56.0+build6-0ubuntu0.14.04.1
thunderbird 18.10 cosmic
Fixed 1:52.4.0+build1-0ubuntu2
18.04 LTS bionic
Fixed 1:52.4.0+build1-0ubuntu2
17.10 artful
Fixed 1:52.4.0+build1-0ubuntu2
17.04 zesty
Fixed 1:52.4.0+build1-0ubuntu0.17.04.2
16.04 LTS xenial
Fixed 1:52.4.0+build1-0ubuntu0.16.04.2
14.04 LTS trusty
Fixed 1:52.4.0+build1-0ubuntu0.14.04.2
nss 18.10 cosmic
Fixed 2:3.32-1ubuntu3
18.04 LTS bionic
Fixed 2:3.32-1ubuntu3
17.10 artful
Fixed 2:3.32-1ubuntu3
17.04 zesty
Fixed 2:3.28.4-0ubuntu0.17.04.3
16.04 LTS xenial
Fixed 2:3.28.4-0ubuntu0.16.04.3
14.04 LTS trusty
Fixed 2:3.28.4-0ubuntu0.14.04.3

Patch details

For informational purposes only. We recommend not to cherry-pick updates. How can I get the fixes?

Package Patch details
nss

Severity score breakdown

Parameter Value
Base score 7.5 · High
Attack vector Network
Attack complexity Low
Privileges required None
User interaction None
Scope Unchanged
Confidentiality None
Integrity impact None
Availability impact High
Vector CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

References

Related Ubuntu Security Notices (USN)

    • USN-3436-1
    • Thunderbird vulnerabilities
    • 11 October 2017
    • USN-3435-1
    • Firefox vulnerabilities
    • 2 October 2017

Other references