Application crash via recursive union leafrefs
Published Jan 22, 2020 · Updated Aug 5, 2024
Uncontrolled recursion in CESNET libyang before 1.0-r1 allows attackers to crash parsing applications with a crafted YANG file. When lys_parse_path resolves a self-referential union typedef containing a leafref, lys_copy_union_leafrefs repeatedly follows the cycle until the process stack is exhausted. Exploitation requires an application to accept and parse the malicious schema; the resulting stack overflow terminates the parsing process without reported data disclosure or modification.
Summary
What happened
Uncontrolled recursion in CESNET libyang before 1.0-r1 allows attackers to crash parsing applications with a crafted YANG file. When lys_parse_path resolves a self-referential union typedef containing a leafref, lys_copy_union_leafrefs repeatedly follows the cycle until the process stack is exhausted. Exploitation requires an application to accept and parse the malicious schema; the resulting stack overflow terminates the parsing process without reported data disclosure or modification.
The record
- CVE
- CVE-2019-20395
- Published
- Jan 22, 2020
- Updated
- Aug 5, 2024
- Vendor
- Unknown vendor
- Product
- Unknown product
- Classifications
- CWE-674, T1499.004
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jan 22, 2020CVE publishedPublication date reported by the CVE source.
- Aug 5, 2024Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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What conditions does exploitation require?
What is affected?
Affected products and versions are unavailable in this record.
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
- Self-referential union YANG crash reproducerproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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