systemd 239 D-Bus Message bus-objects.c bus_process_object memory corruption

Summaryinfo

A vulnerability identified as critical has been detected in systemd 239. This issue affects the function bus_process_object of the file libsystemd/sd-bus/bus-objects.c of the component D-Bus Message Handler. Performing a manipulation results in memory corruption. This vulnerability is known as CVE-2019-6454. Attacking locally is a requirement. No exploit is available.

Detailsinfo

A vulnerability, which was classified as critical, was found in systemd 239. This affects the function bus_process_object of the file libsystemd/sd-bus/bus-objects.c of the component D-Bus Message Handler. The manipulation with an unknown input leads to a memory corruption vulnerability. CWE is classifying the issue as CWE-119. The product performs operations on a memory buffer, but it can read from or write to a memory location that is outside of the intended boundary of the buffer. This is going to have an impact on availability. The summary by CVE is:

An issue was discovered in sd-bus in systemd 239. bus_process_object() in libsystemd/sd-bus/bus-objects.c allocates a variable-length stack buffer for temporarily storing the object path of incoming D-Bus messages. An unprivileged local user can exploit this by sending a specially crafted message to PID1, causing the stack pointer to jump over the stack guard pages into an unmapped memory region and trigger a denial of service (systemd PID1 crash and kernel panic).

The bug was discovered 02/18/2019. The weakness was published 03/21/2019 by Chris Coulson (Website). It is possible to read the advisory at securityfocus.com. This vulnerability is uniquely identified as CVE-2019-6454 since 01/16/2019. Attacking locally is a requirement. A authentication is required for exploitation. Technical details of the vulnerability are known, but there is no available exploit. The pricing for an exploit might be around USD $0-$5k at the moment (estimation calculated on 08/04/2023).

The vulnerability was handled as a non-public zero-day exploit for at least 31 days. During that time the estimated underground price was around $0-$5k. The commercial vulnerability scanner Qualys is able to test this issue with plugin 13476 (McAfee Web Gateway Multiple Vulnerabilities (SB10278)).

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

The vulnerability is also documented in the vulnerability database at SecurityFocus (BID 107081†). Similar entries are available at VDB-113214, VDB-131217 and VDB-133260. Be aware that VulDB is the high quality source for vulnerability data.

Productinfo

Name

• systemd

Version

• 239

License

• open-source

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Be aware that VulDB is the high quality source for vulnerability data.

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