Memory disclosure via unchecked keysym copy failure
Published Oct 10, 2023 · Updated Nov 6, 2025
Out-of-bounds read in X.Org libX11 before 1.8.7 allows remote attackers to disclose client-process memory via crafted X-server replies. _XkbReadKeySyms allocates only 128 extra symbol slots, ignores a failed _XkbReadBufferCopyKeySyms call, and later reads entries that were never copied. Exploitation requires a client to connect to an attacker-controlled X server; the documented consequence is memory disclosure from that client process.
Summary
What happened
Out-of-bounds read in X.Org libX11 before 1.8.7 allows remote attackers to disclose client-process memory via crafted X-server replies. _XkbReadKeySyms allocates only 128 extra symbol slots, ignores a failed _XkbReadBufferCopyKeySyms call, and later reads entries that were never copied. Exploitation requires a client to connect to an attacker-controlled X server; the documented consequence is memory disclosure from that client process.
The record
- CVE
- CVE-2023-43785
- Published
- Oct 10, 2023
- Updated
- Nov 6, 2025
- Vendor
- Red Hat
- Product
- Red Hat Enterprise Linux 8
- Classifications
- CWE-787, CWE-125
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Oct 10, 2023CVE publishedPublication date reported by the CVE source.
- Nov 6, 2025Record updatedLatest update available in the CVE record.
Exploitability
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What conditions does exploitation require?
What is affected?
Published CVSS scores
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Attacks
What attackers are doing with it
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Public exploit references
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Technologies
Your stack
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Your stack
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