CVE-2022-24903

Publication date 5 May 2022

Last updated 24 July 2024


Ubuntu priority

Cvss 3 Severity Score

8.1 · High

Score breakdown

Rsyslog is a rocket-fast system for log processing. Modules for TCP syslog reception have a potential heap buffer overflow when octet-counted framing is used. This can result in a segfault or some other malfunction. As of our understanding, this vulnerability can not be used for remote code execution. But there may still be a slight chance for experts to do that. The bug occurs when the octet count is read. While there is a check for the maximum number of octets, digits are written to a heap buffer even when the octet count is over the maximum, This can be used to overrun the memory buffer. However, once the sequence of digits stop, no additional characters can be added to the buffer. In our opinion, this makes remote exploits impossible or at least highly complex. Octet-counted framing is one of two potential framing modes. It is relatively uncommon, but enabled by default on receivers. Modules `imtcp`, `imptcp`, `imgssapi`, and `imhttp` are used for regular syslog message reception. It is best practice not to directly expose them to the public. When this practice is followed, the risk is considerably lower. Module `imdiag` is a diagnostics module primarily intended for testbench runs. We do not expect it to be present on any production installation. Octet-counted framing is not very common. Usually, it needs to be specifically enabled at senders. If users do not need it, they can turn it off for the most important modules. This will mitigate the vulnerability.

Status

Package Ubuntu Release Status
rsyslog 24.10 oracular
Fixed 8.2204.0-1ubuntu1
24.04 LTS noble
Fixed 8.2204.0-1ubuntu1
23.10 mantic
Fixed 8.2204.0-1ubuntu1
23.04 lunar
Fixed 8.2204.0-1ubuntu1
22.10 kinetic
Fixed 8.2204.0-1ubuntu1
22.04 LTS jammy
Fixed 8.2112.0-2ubuntu2.2
21.10 impish
Fixed 8.2102.0-2ubuntu2.2
20.04 LTS focal
Fixed 8.2001.0-1ubuntu1.3
18.04 LTS bionic
Fixed 8.32.0-1ubuntu4.2
16.04 LTS xenial
14.04 LTS trusty
Needs evaluation

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Severity score breakdown

Parameter Value
Base score 8.1 · High
Attack vector Network
Attack complexity High
Privileges required None
User interaction None
Scope Unchanged
Confidentiality High
Integrity impact High
Availability impact High
Vector CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

References

Related Ubuntu Security Notices (USN)

Other references