CVE-2017-9445
HighSummary
In systemd versions up to 233, certain sizes passed to dns_packet_new in systemd-resolved can cause it to allocate a buffer that's too small. A malicious DNS server can exploit this via a response with a specially crafted TCP payload to trick systemd-resolved into allocating a buffer that's too small, leading to arbitrary data being written beyond its end.
Risk Assessment
An attacker can exploit this vulnerability to overwrite memory, potentially leading to unauthorized access to data or system instability. Organizations should be aware of the risks associated with malicious DNS servers.
Recommendation
It is recommended to update systemd to the latest version to mitigate this vulnerability. Additionally, monitoring and filtering DNS responses from unknown or suspicious sources is advisable.
Other vulnerabilities in systemd
See all- CVE-2026-16742Medium
systemd-homed contains a local privilege escalation bug via arbitrary system group addition to a local, logged in, homed-managed user.
- CVE-2017-15908High
In systemd versions 223 through 235, a remote DNS server can respond with a custom crafted NSEC resource record to trigger an infinite loop in the dns_packet_read_type_window() function of the 'systemd-resolved' service, causing a DoS of the affected service.
- CVE-2016-10156High
A flaw in systemd v228 in /src/basic/fs-util.c caused world writable suid files to be created when using the systemd timers features, allowing local attackers to escalate their privileges to root.
- CVE-2019-3843High
A vulnerability was found in systemd where a service using the DynamicUser property can create a SUID/SGID binary that remains executable with the transient service UID/GID even after the service terminates. A local attacker could exploit this to access resources owned by a potentially different UID/GID.
- CVE-2022-4415Medium
A vulnerability in systemd causes systemd-coredump to ignore the kernel's fs.suid_dumpable setting, potentially leading to a local information leak.
- CVE-2026-40225Medium
In udev in systemd before version 260, local root execution can occur via malicious hardware devices and unsanitized kernel output.
- CVE-2026-40226Medium
In systemd versions 233 through 259 before 260, an escape-to-host action can occur via a crafted optional config file in nspawn.
- CVE-2019-3844High
It was discovered that a systemd service using the DynamicUser property can gain new privileges through the execution of SUID binaries, allowing creation of binaries owned by the service's transient group with the setgid bit set. A local attacker may exploit this flaw to access resources that will be.
- CVE-2021-3997Medium
A flaw was found in systemd where uncontrolled recursion in systemd-tmpfiles may lead to a denial of service at boot time when too many nested directories are created in /tmp.
- CVE-2015-7510Critical
There is a stack-based buffer overflow in the getpwnam and getgrnam functions of the NSS module nss-mymachines in systemd.
Original NVD description (English source)
In systemd through 233, certain sizes passed to dns_packet_new in systemd-resolved can cause it to allocate a buffer that's too small. A malicious DNS server can exploit this via a response with a specially crafted TCP payload to trick systemd-resolved into allocating a buffer that's too small, and subsequently write arbitrary data beyond the end of it.