CVE-2025-53817
BaseFortify
Publication date: 2025-07-17
Last updated on: 2025-11-04
Assigner: GitHub, Inc.
Description
Description
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| 7-zip | 7-zip | to 25.00 (exc) |
Helpful Resources
Exploitability
| CWE ID | Description |
|---|---|
| CWE-476 | The product dereferences a pointer that it expects to be valid but is NULL. |
Attack-Flow Graph
AI Powered Q&A
Can you explain this vulnerability to me?
CVE-2025-53817 is a denial of service vulnerability in 7-Zip's Compound Documents extraction handler caused by a null pointer dereference. The issue occurs due to an unchecked integer overflow during the calculation of cluster sizes, which leads to improper memory allocation. Specifically, when processing an item with a large size, an overflow causes the internal vector pointer to remain null. Later, the program attempts to write to this null pointer, causing a crash (segmentation fault) and thus denial of service. [1]
How can this vulnerability impact me? :
This vulnerability can cause 7-Zip to crash when extracting specially crafted Compound Documents, resulting in a denial of service. This means that an attacker could cause the application to stop functioning by providing malicious archive files, potentially disrupting workflows or automated processes that rely on 7-Zip for extraction. [1]
How can this vulnerability be detected on my network or system? Can you suggest some commands?
This vulnerability can be detected by testing the 7-Zip application with specially crafted Compound Document files that trigger the null pointer dereference and cause a crash or segmentation fault during extraction. A proof-of-concept (PoC) file is available that causes this behavior. Monitoring 7-Zip crashes or segmentation faults (SEGV) during extraction of Compound Documents can indicate exploitation. There are no specific network detection commands provided. On Linux, running 7-Zip extraction under AddressSanitizer (ASAN) can help detect the issue. Example command to test extraction: `7z x crafted_poc_file` where `crafted_poc_file` is the PoC triggering the vulnerability. [1]
What immediate steps should I take to mitigate this vulnerability?
The immediate mitigation step is to upgrade 7-Zip to version 25.00 or later, where the vulnerability has been fixed. Avoid extracting untrusted or suspicious Compound Document files with vulnerable versions of 7-Zip. If upgrading is not immediately possible, consider restricting usage of 7-Zip for untrusted files or using alternative extraction tools that are not affected. [1]