Process hang via EOF comment parsing loop
Published Jun 27, 2023 · Updated Dec 3, 2024
Denial of service in pypdf before 3.9.0 and PyPDF2 2.2.0 and later allows attackers to hang a process with a crafted PDF. The __parse_content_stream parser reads past an end-of-file comment because its loop stops only for carriage-return or newline bytes, not an empty read. Triggering text extraction on the crafted document leaves the current process spinning on one CPU core, blocking that process without increasing memory use.
Summary
What happened
Denial of service in pypdf before 3.9.0 and PyPDF2 2.2.0 and later allows attackers to hang a process with a crafted PDF. The __parse_content_stream parser reads past an end-of-file comment because its loop stops only for carriage-return or newline bytes, not an empty read. Triggering text extraction on the crafted document leaves the current process spinning on one CPU core, blocking that process without increasing memory use.
The record
- CVE
- CVE-2023-36464
- Published
- Jun 27, 2023
- Updated
- Dec 3, 2024
- Vendor
- py-pdf
- Product
- pypdf
- Classifications
- CWE-835, T1499.004
- Attack vector
- local
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jun 27, 2023CVE publishedPublication date reported by the CVE source.
- Dec 3, 2024Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=PyPDF2: >= 2.2.0
- Affected versionversion=pypdf: < 3.90
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- Upstream crafted-PDF reproductionproof of concept · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
See the directory against your own environment.
Your stack
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