Envoy is a high-performance edge/middle/service proxy. The regex expression is compiled for every request and can result in high CPU usage …
Envoy is a high-performance edge/middle/service proxy. The regex expression is compiled for every request and can result in high CPU usage and increased request latency when multiple routes are configured with such matchers. This issue has been addressed in released 1.29.1, 1.28.1, 1.27.3, and 1.26.7. Users are advised to upgrade. There are no known workarounds for this vulnerability.
The product performs CPU computations using algorithms that are not as efficient as they could be for the needs of the developer, i.e., the computations can be optimized further.
https://cwe.mitre.org/data/definitions/1176.html →Open in CWE collection →The product does not properly control the allocation and maintenance of a limited resource.
https://cwe.mitre.org/data/definitions/400.html →Open in CWE collection →An attacker initiates a resource depletion attack where a large number of small XML messages are delivered at a sufficiently rapid rate to cause a denial of service or crash of the target. Transactions such as repetitive SOAP transactions can deplete resources faster than a simple flooding attack because of the additional resources used by the SOAP protocol and the resources necessary to process SOAP messages. The transactions used are immaterial as long as they cause resource utilization on the target. In other words, this is a normal flooding attack augmented by using messages that will require extra processing on the target.
https://capec.mitre.org/data/definitions/147.html →Open in CAPEC collection →An adversary attempts to deny legitimate users access to a resource by continually engaging a specific resource in an attempt to keep the resource tied up as long as possible. The adversary's primary goal is not to crash or flood the target, which would alert defenders; rather it is to repeatedly perform actions or abuse algorithmic flaws such that a given resource is tied up and not available to a legitimate user. By carefully crafting a requests that keep the resource engaged through what is seemingly benign requests, legitimate users are limited or completely denied access to the resource.
https://capec.mitre.org/data/definitions/227.html →Open in CAPEC collection →An adversary may execute an attack on a program that uses a poor Regular Expression(Regex) implementation by choosing input that results in an extreme situation for the Regex. A typical extreme situation operates at exponential time compared to the input size. This is due to most implementations using a Nondeterministic Finite Automaton(NFA) state machine to be built by the Regex algorithm since NFA allows backtracking and thus more complex regular expressions.
https://capec.mitre.org/data/definitions/492.html →Open in CAPEC collection →