Code execution via out-of-bounds output-page write
Published Mar 16, 2022 · Updated Aug 3, 2024
Heap buffer overflow in HTMLDOC before 1.9.12 allows context-dependent attackers to execute code or crash the process through crafted HTML. The pspdf_prepare_outpages() loop advances num_outpages beyond its num_pages-sized allocation because the chapter loop lacks an output-count bound. Exploitation requires HTMLDOC to convert attacker-controlled HTML to PostScript or PDF; the demonstrated result is a heap overwrite and process abort, while the advisory also reports code execution.
Summary
What happened
Heap buffer overflow in HTMLDOC before 1.9.12 allows context-dependent attackers to execute code or crash the process through crafted HTML. The pspdf_prepare_outpages() loop advances num_outpages beyond its num_pages-sized allocation because the chapter loop lacks an output-count bound. Exploitation requires HTMLDOC to convert attacker-controlled HTML to PostScript or PDF; the demonstrated result is a heap overwrite and process abort, while the advisory also reports code execution.
The record
- CVE
- CVE-2021-23165
- Published
- Mar 16, 2022
- Updated
- Aug 3, 2024
- Vendor
- HTMLDOC Project
- Product
- HTMLDOC
- Classifications
- CWE-122, CWE-787, T1203
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Mar 16, 2022CVE publishedPublication date reported by the CVE source.
- Aug 3, 2024Record 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=before v1.9.12
What conditions does exploitation require?
What is affected?
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
- poc2.zip heap-overflow proof of conceptfunctional · 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
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