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GHSA-98vv-pw6r-q6q4 BIT-pillow-2021-23437 CVE-2021-23437 PYSEC-2021-317 SNYK-PYTHON-PILLOW-1319443

Uncontrolled Resource Consumption in pillow

High PyPI
Severity
0.0 / 10
High · CVSS 4.0
Exploit chance (EPSS)
3.24%
Chance of exploitation in the next 30 days. Higher than 88.29% of scored vulnerabilities.
Known exploited
No
Not in CISA's catalog
Weakness
CWE-125 Out-of-bounds Read
CWE-400 Uncontrolled Resource Consumption
Fix
8.3.2
Upgrade pillow to this version or later

Description

The package pillow 5.2.0 and before 8.3.2 are vulnerable to Regular Expression Denial of Service (ReDoS) via the getrgb function.

Affected versions

PyPI

PackageVulnerableFixed in
pillow
>= 5.2.0, < 8.3.2
8.3.2
pillow
< 8.3.2
8.3.2

How to fix

Move to the fixed version or later with your package manager, update the lockfile, and run your tests. If the package only arrives through another dependency, upgrade that dependency first. If none of its releases pulls a fixed version yet, force the version with your package manager's override.

pillow PyPI → 8.3.2

pip
pip install --upgrade "pillow>=8.3.2"
poetry
poetry add "pillow>=8.3.2"
uv
uv add "pillow>=8.3.2"

Severity breakdown

CVSS 4.0 0.0

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

Attack vector
Network
Attack complexity
Low
Attack requirements
None
Privileges required
None
User interaction
None
Confidentiality (vulnerable system)
None
Integrity (vulnerable system)
None
Availability (vulnerable system)
High
Confidentiality (subsequent systems)
None
Integrity (subsequent systems)
None
Availability (subsequent systems)
None

CVSS 3.1 7.5

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

Weakness

CWE-125: Out-of-bounds Read

The product reads data past the end, or before the beginning, of the intended buffer.

How to prevent it
  • Implementation: Assume all input is malicious. Use an "accept known good" input validation strategy, i.e., use a list of acceptable inputs that strictly conform to specifications. Reject any input that does not strictly conform to specifications, or transform it into something that does. When performing input validation, consider all potentially relevant properties, including length, type of input, the full range of acceptable values, missing or extra inputs, syntax, consistency across related fields, and conformance to business rules. As an example of business rule logic, "boat" may be syntactically valid because it only contains alphanumeric characters, but it is not valid if the input is only expected to contain colors such as "red" or "blue." Do not rely exclusively on looking for malicious or malformed inputs. This is likely to miss at least one undesirable input, especially if the code's environment changes. This can give attackers enough room to bypass the intended validation. However, denylists can be useful for detecting potential attacks or determining which inputs are so malformed that they should be rejected outright. To reduce the likelihood of introducing an out-of-bounds read, ensure that you validate and ensure correct calculations for any length argument, buffer size calculation, or offset. Be especially careful of relying on a sentinel (i.e. special character such as NUL) in untrusted inputs.
  • Architecture and Design: Use a language that provides appropriate memory abstractions.

CWE-400: Uncontrolled Resource Consumption

The product does not properly control the allocation and maintenance of a limited resource.

How to prevent it
  • Architecture and Design: Design throttling mechanisms into the system architecture. The best protection is to limit the amount of resources that an unauthorized user can cause to be expended. A strong authentication and access control model will help prevent such attacks from occurring in the first place. The login application should be protected against DoS attacks as much as possible. Limiting the database access, perhaps by caching result sets, can help minimize the resources expended. To further limit the potential for a DoS attack, consider tracking the rate of requests received from users and blocking requests that exceed a defined rate threshold.
  • Architecture and Design: Mitigation of resource exhaustion attacks requires that the target system either: recognizes the attack and denies that user further access for a given amount of time, or uniformly throttles all requests in order to make it more difficult to consume resources more quickly than they can again be freed. The first of these solutions is an issue in itself though, since it may allow attackers to prevent the use of the system by a particular valid user. If the attacker impersonates the valid user, they may be able to prevent the user from accessing the server in question. The second solution is simply difficult to effectively institute -- and even when properly done, it does not provide a full solution. It simply makes the attack require more resources on the part of the attacker.
  • Architecture and Design: Ensure that protocols have specific limits of scale placed on them.
  • Implementation: Ensure that all failures in resource allocation place the system into a safe posture.

References

Timeline

  1. Published
  2. Last updated by the source
  3. Latest EPSS score
AdvisorySeverityWhy it's related
PYSEC-2023-175
Pillow versions before v10.0.1 bundled libwebp binaries in wheels that are vulnerable to CVE-2023-5129 (previously CVE-2023-4863).
High Known exploited Also affects pillow
GHSA-j7hp-h8jx-5ppr
libwebp: OOB write in BuildHuffmanTable
High Known exploited Also affects pillow
GHSA-78g4-xqwv-q3g8
Pillow: Bundled libopenjp2 2.5.4 in all wheels since 11.1.0 carries OSV-2025-219 heap-buffer-overflow write reachable from Image.open().load()
High Also affects pillow
GHSA-654x-cwwv-5j9c
Pillow: Arrow export leaks stale heap memory when PILLOW_ALIGNMENT > 1
Medium Also affects pillow
GHSA-xvh5-g6gv-559v
Pillow: Memory disclosure and segfault in libtiff encoder via crafted TIFF tags
High Also affects pillow
GHSA-g7cr-3p24-7wf7
Pillow: Heap buffer overflow writing JPEG comment after ICC profile fills buffer
High Also affects pillow
GHSA-9v9v-9qvf-h2hj
Pillow: Heap over-read in WMF/EMF rendering via 16-bit dimension truncation (Windows builds)
High Also affects pillow
GHSA-g4qv-2jxx-769h
Pillow: PNG eXIf chunk makes EXIF parsing run in quadratic time
Medium Also affects pillow
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