CVE-2023-46136
ADVISORY - githubSummary
Werkzeug multipart data parser needs to find a boundary that may be between consecutive chunks. That's why parsing is based on looking for newline characters. Unfortunately, code looking for partial boundary in the buffer is written inefficiently, so if we upload a file that starts with CR or LF and then is followed by megabytes of data without these characters: all of these bytes are appended chunk by chunk into internal bytearray and lookup for boundary is performed on growing buffer.
This allows an attacker to cause a denial of service by sending crafted multipart data to an endpoint that will parse it. The amount of CPU time required can block worker processes from handling legitimate requests. The amount of RAM required can trigger an out of memory kill of the process. If many concurrent requests are sent continuously, this can exhaust or kill all available workers.
Common Weakness Enumeration (CWE)
Inefficient Algorithmic Complexity
GitHub
CVSS SCORE
5.7medium| Package | Type | OS Name | OS Version | Affected Ranges | Fix Versions |
|---|---|---|---|---|---|
| werkzeug | pypi | - | - | <2.3.8 | 2.3.8 |
| werkzeug | pypi | - | - | >=3.0.0,<3.0.1 | 3.0.1 |
CVSS:3 Severity and metrics
The CVSS metrics represent different qualitative aspects of a vulnerability that impact the overall score, as defined by the CVSS Specification.
The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed below, up to and including the entire Internet. Such a vulnerability is often termed “remotely exploitable” and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers). An example of a network attack is an attacker causing a denial of service (DoS) by sending a specially crafted TCP packet across a wide area network (e.g., CVE-2004-0230).
Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success when attacking the vulnerable component.
The attacker requires privileges that provide basic user capabilities that could normally affect only settings and files owned by a user. Alternatively, an attacker with Low privileges has the ability to access only non-sensitive resources.
The vulnerable system can be exploited without interaction from any user.
An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
There is no loss of confidentiality.
There is no loss of trust or accuracy within the impacted component.
There is a total loss of availability, resulting in the attacker being able to fully deny access to resources in the impacted component; this loss is either sustained (while the attacker continues to deliver the attack) or persistent (the condition persists even after the attack has completed). Alternatively, the attacker has the ability to deny some availability, but the loss of availability presents a direct, serious consequence to the impacted component.
NIST
CVSS SCORE
8highAlpine
-
Debian
-
CVSS SCORE
N/AlowUbuntu
3.9
CVSS SCORE
7.5mediumRed Hat
3.9
CVSS SCORE
7.5mediumChainguard
CGA-28xq-7c2r-6pqc
-
Chainguard
CGA-359g-9qp6-mwmm
-
Chainguard
CGA-362w-xpjf-5557
-
Chainguard
CGA-3xrx-g66v-9vhw
-
Chainguard
CGA-cjqh-m7mf-8p58
-
Chainguard
CGA-p9q7-2f52-g93c
-
Chainguard
CGA-q6f7-x3w6-52gc
-
Chainguard
CGA-v94x-q6m7-qgqv
-
Chainguard
CGA-xm82-6r9q-w4j8
-
Photon
CVE-2023-46136
-
CVSS SCORE
7.5highminimos
MINI-66xx-vx53-hxwv
-
minimos
MINI-6mcg-6ffr-jqmp
-