CVE-2020-10188 – telnet-server: no bounds checks in nextitem() function allows to remotely execute arbitrary code

https://notcve.org/view.php?id=CVE-2020-10188

utility.c in telnetd in netkit telnet through 0.17 allows remote attackers to execute arbitrary code via short writes or urgent data, because of a buffer overflow involving the netclear and nextitem functions. El archivo utility.c en telnetd en netkit telnet versiones hasta 0.17, permite a atacantes remotos ejecutar código arbitrario por medio de escrituras cortas o datos urgentes, debido a un desbordamiento del búfer que involucra a las funciones netclear y nextitem. A vulnerability was found where incorrect bounds checks in the telnet server’s (telnetd) handling of short writes and urgent data, could lead to information disclosure and corruption of heap data. An unauthenticated remote attacker could exploit these bugs by sending specially crafted telnet packets to achieve arbitrary code execution in the telnet server. • https://appgateresearch.blogspot.com/2020/02/bravestarr-fedora-31-netkit-telnetd_28.html https://github.com/krb5/krb5-appl/blob/d00cd671dfe945791b33d4f1f6a5c57ae1667ef8/telnet/telnetd/utility.c#L205-L216 https://lists.debian.org/debian-lts-announce/2020/05/msg00012.html https://lists.debian.org/debian-lts-announce/2020/08/msg00038.html https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/7FMTRRQTYKWZD2GMXX3GLZV46OLPCLVK https://lists.fedoraproject.org/archives/list/package-announce%40l • CWE-119: Improper Restriction of Operations within the Bounds of a Memory Buffer CWE-120: Buffer Copy without Checking Size of Input ('Classic Buffer Overflow') •