Snort 3 vulnerabilities

The vulnerability in Snort 2.9.7.0-WIN32 related to an untrusted search path allows remote attackers to execute arbitrary code and conduct DLL hijacking attacks via a malicious tcapi.dll file located in the same folder as a processed pcap file.

A vulnerability in Cisco Snort 3 software related to out-of-bounds writes (CWE-787). It was discovered during an internal security review and fixed in hardening releases.

The Snort 3 control channel socket implementation lacks authentication when a local user connects to the socket. An authenticated local attacker with low privileges can execute arbitrary commands as the Snort 3 process user and read or write the process memory.

Multiple Cisco products are affected by a vulnerability in the memory management implementation of Snort 3 that could allow an unauthenticated, remote attacker to cause the Snort 3 Detection Engine to restart, interrupting packet inspection. The issue is due to incomplete error checking when Snort 3 processes files, which could cause unreleased memory.

Cisco Snort 3 contains multiple internally discovered vulnerabilities related to uncontrolled resource consumption (CWE-400) that have been addressed in software hardening releases. Technical details of individual cases were not disclosed in the description.

Cisco's Open Source Snort 3 software engineering team conducted an internal security review, resulting in hardening releases that address multiple internally discovered vulnerabilities. The vulnerabilities tracked by CVE-2026-20291 relate to improper privilege management (CWE-269).

Cisco Snort 3 contains multiple internally discovered vulnerabilities related to incorrect calculation (CWE-682) that have been addressed in software hardening releases. Technical details of individual cases were not disclosed in the description.

A vulnerability in the Snort 3 VBA Decompression Engine of multiple Cisco products allows an unauthenticated, remote attacker to cause the Snort 3 Detection Engine to restart unexpectedly, resulting in a denial of service (DoS). The flaw is due to improper range checking when decompressing user-controlled VBA data. Sending crafted VBA data can cause a stack overflow and DoS condition.

A vulnerability in the Snort 3 Teredo Detection Engine of multiple Cisco products allows an unauthenticated, remote attacker to cause the Snort 3 Detection Engine to restart, interrupting packet inspection. The flaw is due to incomplete error checking when parsing Teredo packets. Sending a crafted Teredo packet to a targeted device can cause an unexpected restart and DoS condition.

A vulnerability in the Snort 3 Generic Routing Encapsulation (GRE) Detection Engine of multiple Cisco products allows an unauthenticated, remote attacker to cause the Snort 3 Detection Engine to restart, interrupting packet inspection. The flaw is due to incomplete error checking when parsing GRE packets. Sending a crafted GRE packet to a targeted device can cause an unexpected restart and DoS condition.

A vulnerability in the Snort 3 NetFlow Detection Engine of multiple Cisco products allows an unauthenticated, remote attacker to cause the Snort 3 Detection Engine to restart, interrupting packet inspection. The flaw is due to incomplete error checking when parsing UDP Netflow Protocol packets. Sending a single crafted Netflow packet through an established connection can cause an unexpected restart and DoS condition.

A vulnerability in the Snort 3 SMTP MIME Decoder of multiple Cisco products allows an unauthenticated, remote attacker to cause the Snort 3 Detection Engine to restart. The flaw is due to a lack of error checking when parsing MIME fields of the SMTP header. Sending crafted SMTP packets through an established connection can cause an unexpected restart and denial of service (DoS) condition.

Vulnerability in the Snort 3 detection engine in multiple Cisco products allows an unauthenticated, remote attacker to cause the engine to restart, interrupting packet inspection. It is due to incomplete error checking when parsing RPC data.

Multiple Cisco products are affected by a vulnerability in the Snort 3 detection engine that could allow an unauthenticated, remote attacker to cause the Snort 3 Detection Engine to restart, resulting in an interruption of packet inspection. This vulnerability is due to incomplete error checking when parsing the Multicast DNS fields of the HTTP header. An attacker could exploit this vulnerability by sending crafted HTTP packets through an established connection to be parsed by Snort 3. A successful exploit could allow the attacker to cause a DoS condition when the Snort 3 Detection Engine unexpectedly restarts.

Multiple Cisco products are affected by a vulnerability in the Snort 3 Detection Engine that could allow an unauthenticated, remote attacker to cause the Snort 3 Detection Engine to restart, resulting in an interruption of packet inspection. This vulnerability is due to an error in the JSTokenizer normalization logic when the HTTP inspection normalizes JavaScript. An attacker could exploit this vulnerability by sending crafted HTTP packets through an established connection that is parsed by Snort 3. A successful exploit could allow the attacker to cause a DoS condition when the Snort 3 Detection Engine restarts unexpectedly. JSTokenizer is not enabled by default.

Multiple Cisco products are affected by vulnerabilities in the Snort 3 VBA feature that could allow an unauthenticated, remote attacker to cause the Snort 3 Detection Engine to crash. These vulnerabilities are due to improper error checking when decompressing VBA data. An attacker could exploit these vulnerabilities by sending crafted VBA data to the Snort 3 Detection Engine on the targeted device. A successful exploit could allow the attacker to cause the Snort 3 Detection Engine to unexpectedly restart, causing a DoS condition.

Multiple Cisco products are affected by a vulnerability in the Snort 3 Detection Engine that could allow an unauthenticated, remote attacker to cause the Snort 3 Detection Engine to restart, resulting in an interruption of packet inspection. This vulnerability is due to incomplete parsing of the SSL handshake ingress packets. An attacker could exploit this vulnerability by sending crafted SSL handshake packets. A successful exploit could allow the attacker to cause a denial of service (DoS) condition when the Snort 3 Detection Engine restarts unexpectedly.

Multiple Cisco products are affected by a vulnerability in the Snort 3 HTTP Decoder caused by incomplete error checking when parsing MIME fields of the HTTP header. An unauthenticated remote attacker can send crafted HTTP packets, causing the Snort 3 Detection Engine to unexpectedly restart.

A vulnerability in the Snort 3 HTTP Decoder due to a buffer handling error when parsing MIME fields of the HTTP header can result in a buffer under-read. An unauthenticated remote attacker can send crafted HTTP packets to cause information disclosure or a crash of the Snort 3 Detection Engine.

A vulnerability in the Modbus preprocessor of the Snort detection engine could allow an unauthenticated, remote attacker to cause a denial of service (DoS). The issue is due to an integer overflow while processing Modbus traffic. Exploitation involves sending crafted Modbus traffic.

A vulnerability in the IP geolocation rules of Snort 3 could allow an unauthenticated, remote attacker to bypass IP address restrictions. This is due to improper parsing of the configuration for IP geolocation rules.

Multiple Cisco products are affected by a vulnerability in Snort access control policies that could allow an unauthenticated, remote attacker to bypass configured policies. This is due to a logic error when access control policies are populated. An attacker could exploit this by establishing a connection, potentially bypassing access control rules.

A vulnerability in Snort rules in multiple Cisco products could allow an unauthenticated, remote attacker to cause a denial of service (DoS). The issue is due to improper handling of Block with Reset or Interactive Block with Reset actions if a rule is configured without proper constraints. Exploitation involves sending a crafted IP packet.

A vulnerability in the Snort detection engine of multiple Cisco products when processing ICMP traffic could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition. The issue is due to improper memory resource management while processing ICMP packets. An attacker could send a series of ICMP packets through an affected device, potentially exhausting resources and causing a reload.

A vulnerability in the Snort application detection engine of multiple Cisco products could allow an unauthenticated, remote attacker to bypass configured policies. The issue is due to a flaw in the detection algorithm. An attacker could send crafted packets through an affected system, potentially bypassing policies and delivering a malicious payload.

A vulnerability with TCP Fast Open (TFO) when used with the Snort detection engine in multiple Cisco products could allow an unauthenticated, remote attacker to bypass a configured file policy for HTTP. The issue is due to incorrect detection of the HTTP payload if it is contained at least partially within the TFO connection handshake. An attacker could send crafted TFO packets with an HTTP payload through an affected device, potentially bypassing the policy and delivering a malicious payload.

A vulnerability in the Snort detection engine affecting multiple Cisco products could allow an unauthenticated, remote attacker to bypass a configured file policy for HTTP. The issue is due to incorrect handling of an HTTP range header. An attacker could send crafted HTTP packets to bypass file policy and deliver a malicious payload.

A vulnerability in the Snort detection engine of multiple Cisco products could allow an unauthenticated, remote attacker to bypass a configured File Policy for HTTP. The issue is due to incorrect detection of modified HTTP packets used in chunked responses. An attacker could send crafted HTTP packets through an affected device, potentially bypassing the policy and delivering a malicious payload.

A vulnerability in the Snort detection engine of multiple Cisco products could allow an unauthenticated, remote attacker to bypass configured file policies. The issue is due to errors in how Snort handles specific HTTP responses. An attacker could send crafted HTTP packets through an affected system, potentially bypassing policies and delivering a malicious payload.

Snort 1.6, when running in straight ASCII packet logging mode or IDS mode with straight decoded ASCII packet logging selected, allows remote attackers to cause a denial of service (crash) by sending non-IP protocols that Snort does not know about, as demonstrated by an nmap protocol scan.