Denial of service via catastrophic regex backtracking
Published Sep 6, 2022 · Updated Apr 22, 2025
Inefficient regular expression complexity in Shescape 1.5.1 through 1.5.9 allows remote attackers to interrupt services via crafted input. The escape and escapeAll functions apply two Bash/Dash escaping regular expressions whose nested quantifiers trigger polynomial backtracking or quadratic runtime on specially constructed strings, especially when interpolation is enabled. The attack requires an application to pass attacker-controlled text into those functions and can cause service hangs or severe slowdown without providing data access or modification.
Summary
What happened
Inefficient regular expression complexity in Shescape 1.5.1 through 1.5.9 allows remote attackers to interrupt services via crafted input. The escape and escapeAll functions apply two Bash/Dash escaping regular expressions whose nested quantifiers trigger polynomial backtracking or quadratic runtime on specially constructed strings, especially when interpolation is enabled. The attack requires an application to pass attacker-controlled text into those functions and can cause service hangs or severe slowdown without providing data access or modification.
The record
- CVE
- CVE-2022-36064
- Published
- Sep 6, 2022
- Updated
- Apr 22, 2025
- Vendor
- Eric Cornelissen
- Product
- Shescape
- Classifications
- CWE-1333, T1499.003
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Sep 6, 2022CVE publishedPublication date reported by the CVE source.
- Apr 22, 2025Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
Compare your product and version with the public record. A matching version still requires validation against your environment.
Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=>= 1.5.1, < 1.5.10
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
No public exploit references are available in this record.
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
Check the software in your environment
Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.
Book a demo