#dos

### Impact A remote Matrix user with malicious intent, sharing a room with Synapse instances before 1.105.1, can dispatch specially crafted events to exploit a weakness in how the auth chain cover index is calculated. This can induce high CPU consumption and accumulate excessive data in the database of such instances, resulting in a denial of service. Servers in private federations, or those that do not federate, are not affected. ### Patches Server administrators should upgrade to 1.105.1 or later. ### Workarounds One can: - ban the malicious users or ACL block servers from the rooms; and/or - leave the room and purge the room using the admin API ### For more information If you have any questions or comments about this advisory, please email us at [security AT element.io](mailto:security@element.io).

Debian Linux Security Advisory 5673-1 - Charles Fol discovered that the iconv() function in the GNU C library is prone to a buffer overflow vulnerability when converting strings to the ISO-2022-CN-EXT character set, which may lead to denial of service (application crash) or the execution of arbitrary code.

Ubuntu Security Notice 6746-1 - It was discovered that Google Guest Agent and Google OS Config Agent incorrectly handled certain JSON files. An attacker could possibly use this issue to cause a denial of service.

Debian Linux Security Advisory 5672-1 - Several vulnerabilities have been discovered in the OpenJDK Java runtime, which may result in denial of service or information disclosure.

Ubuntu Security Notice 6728-3 - USN-6728-1 fixed vulnerabilities in Squid. The fix for CVE-2023-5824 caused Squid to crash in certain environments on Ubuntu 20.04 LTS and was disabled in USN-6728-2. The problematic fix for CVE-2023-5824 has now been corrected and reinstated in this update.

Debian Linux Security Advisory 5671-1 - Several vulnerabilities have been discovered in the OpenJDK Java runtime, which may result in denial of service or information disclosure.

Debian Linux Security Advisory 5670-1 - Multiple security issues were discovered in Thunderbird, which could result in denial of service or the execution of arbitrary code.

Ubuntu Security Notice 6744-2 - USN-6744-1 fixed a vulnerability in Pillow. This update provides the corresponding updates for Pillow in Ubuntu 20.04 LTS. Hugo van Kemenade discovered that Pillow was not properly performing bounds checks when processing an ICC file, which could lead to a buffer overflow. If a user or automated system were tricked into processing a specially crafted ICC file, an attacker could possibly use this issue to cause a denial of service or execute arbitrary code.

Ubuntu Security Notice 6744-1 - Hugo van Kemenade discovered that Pillow was not properly performing bounds checks when processing an ICC file, which could lead to a buffer overflow. If a user or automated system were tricked into processing a specially crafted ICC file, an attacker could possibly use this issue to cause a denial of service or execute arbitrary code.

Red Hat Security Advisory 2024-1963-03 - An update for golang is now available for Red Hat Enterprise Linux 9. Issues addressed include a denial of service vulnerability.