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CWE-416 (释放后使用) — Vulnerability Class 2577

2577 vulnerabilities classified as CWE-416 (释放后使用). AI Chinese analysis included.

CWE-416, Use After Free, is a critical memory safety weakness occurring when a program continues to reference a memory location after it has been deallocated. Attackers typically exploit this vulnerability by freeing an object and then rapidly reallocating that same memory block with attacker-controlled data. Because the original pointer still points to the now-invalid address, the application may inadvertently execute malicious code or corrupt memory structures, often leading to arbitrary code execution or denial of service. To prevent this, developers must rigorously manage memory lifecycles by nullifying pointers immediately after freeing them, ensuring no dangling references remain. Utilizing modern programming languages with automatic garbage collection or employing static analysis tools to detect invalid memory accesses further mitigates the risk, ensuring that freed memory is never accessed again during the program’s execution.

MITRE CWE Description
The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.
Common Consequences (4)
IntegrityModify Memory
The use of previously freed memory may corrupt valid data, if the memory area in question has been allocated and used properly elsewhere.
AvailabilityDoS: Crash, Exit, or Restart
If chunk consolidation occurs after the use of previously freed data, the process may crash when invalid data is used as chunk information.
ConfidentialityRead Memory
Read operations on freed memory can sometimes leak sensitive information instead of causing a crash
Integrity, Confidentiality, AvailabilityExecute Unauthorized Code or Commands
If malicious data is entered before chunk consolidation can take place, it may be possible to take advantage of a write-what-where primitive to execute arbitrary code. If the newly allocated data happens to hold a class, in C++ for example, various function pointers may be scattered within the heap …
Mitigations (2)
Architecture and DesignChoose a language that provides automatic memory management.
ImplementationWhen freeing pointers, be sure to set them to NULL once they are freed. However, the utilization of multiple or complex data structures may lower the usefulness of this strategy.
Effectiveness: Defense in Depth
Examples (2)
The following example demonstrates the weakness.
#include <stdio.h> #include <unistd.h> #define BUFSIZER1 512 #define BUFSIZER2 ((BUFSIZER1/2) - 8) int main(int argc, char **argv) { char *buf1R1; char *buf2R1; char *buf2R2; char *buf3R2; buf1R1 = (char *) malloc(BUFSIZER1); buf2R1 = (char *) malloc(BUFSIZER1); free(buf2R1); buf2R2 = (char *) malloc(BUFSIZER2); buf3R2 = (char *) malloc(BUFSIZER2); strncpy(buf2R1, argv[1], BUFSIZER1-1); free(buf1R1); free(buf2R2); free(buf3R2); }
Bad · C
The following code illustrates a use after free error:
char* ptr = (char*)malloc (SIZE); if (err) { abrt = 1; free(ptr); } ... if (abrt) { logError("operation aborted before commit", ptr); }
Bad · C
CVE IDTitleCVSSSeverityPublished
CVE-2022-28250 Adobe Acrobat Reader DC Annotation Use-After-Free Information Disclosure Vulnerability — Acrobat Reader 5.5 Medium2022-05-11
CVE-2022-28242 Adobe Acrobat Reader DC Annotation Use-After-Free Remote Code Execution Vulnerability — Acrobat Reader 7.8 High2022-05-11
CVE-2022-28240 Adobe Acrobat Reader DC Annotation Use-After-Free Remote Code Execution Vulnerability — Acrobat Reader 7.8 High2022-05-11
CVE-2022-28238 Adobe Acrobat Reader DC Annotation Use-After-Free Remote Code Execution Vulnerability — Acrobat Reader 7.8 -2022-05-11
CVE-2022-28237 Adobe Acrobat Reader DC Annotation Use-After-Free Remote Code Execution Vulnerability — Acrobat Reader 7.8 -2022-05-11
CVE-2022-28235 Adobe Acrobat Reader DC AcroForm Use-After-Free Remote Code Execution Vulnerability — Acrobat Reader 7.8 -2022-05-11
CVE-2022-28233 Adobe Acrobat Reader DC Annotation Use-After-Free Remote Code Execution Vulnerability — Acrobat Reader 7.8 -2022-05-11
CVE-2022-28232 Adobe Acrobat Reader DC Collab Object Use-After-Free Information Disclosure Vulnerability — Acrobat Reader 7.8 -2022-05-11
CVE-2022-28230 Adobe Acrobat Reader DC AcroForm calculateNow Use-After-Free Remote Code Execution Vulnerability — Acrobat Reader 7.8 -2022-05-11
CVE-2022-27802 Adobe Acrobat Reader DC Annotation Use-After-Free Remote Code Execution Vulnerability — Acrobat Reader 7.8 -2022-05-11
CVE-2022-27801 Adobe Acrobat Reader DC Annotation Use-After-Free Remote Code Execution Vulnerability — Acrobat Reader 7.8 -2022-05-11
CVE-2022-27800 Adobe Acrobat Reader DC Annotation Use-After-Free Remote Code Execution Vulnerability — Acrobat Reader 7.8 -2022-05-11
CVE-2022-27799 Adobe Acrobat Reader DC AcroForm Use-After-Free Remote Code Execution Vulnerability — Acrobat Reader 7.8 -2022-05-11
CVE-2022-27797 Adobe Acrobat Reader DC Annotation Use-After-Free Remote Code Execution Vulnerability — Acrobat Reader 7.8 -2022-05-11
CVE-2022-27796 Adobe Acrobat Reader DC AcroForm isBoxChecked Use-After-Free Remote Code Execution Vulnerability — Acrobat Reader 7.8 -2022-05-11
CVE-2022-27795 Adobe Acrobat Reader DC AcroForm isDefaultChecked Use-After-Free Remote Code Execution Vulnerability — Acrobat Reader 7.8 -2022-05-11
CVE-2022-27790 Adobe Acrobat Reader DC Font Parsing Use-After-Free Remote Code Execution Vulnerability — Acrobat Reader 7.8 -2022-05-11
CVE-2022-27789 Adobe Acrobat Reader DC AcroForm Use-After-Free Remote Code Execution Vulnerability — Acrobat Reader 7.8 -2022-05-11
CVE-2022-27786 Adobe Acrobat Reader DC Font Parsing Use-After-Free Remote Code Execution Vulnerability — Acrobat Reader 7.8 -2022-05-11
CVE-2022-27785 Adobe Acrobat Reader DC Font Parsing Use-After-Free Remote Code Execution Vulnerability — Acrobat Reader 7.8 -2022-05-11
CVE-2022-24104 Adobe Acrobat Reader DC Annotation Use-After-Free Remote Code Execution Vulnerability — Acrobat Reader 7.8 -2022-05-11
CVE-2022-24103 Adobe Acrobat Reader DC Annotation Use-After-Free Remote Code Execution Vulnerability — Acrobat Reader 7.8 -2022-05-11
CVE-2022-24102 Adobe Acrobat Reader DC Annotation Use-After-Free Remote Code Execution Vulnerability — Acrobat Reader 7.8 -2022-05-11
CVE-2022-24101 Adobe Acrobat Reader DC Annotation Use-After-Free Information Disclosure Vulnerability — Acrobat Reader 5.5 -2022-05-11
CVE-2022-1616 Use after free in append_command in vim/vim — vim/vim 7.8 -2022-05-07
CVE-2022-28279 Adobe Photoshop Font Parsing Use-After-Free Remote Code Execution Vulnerability — Photoshop 7.8 -2022-05-06
CVE-2022-28271 Adobe Photoshop PDF File Parsing Use-After-Free Remote Code Execution Vulnerability — Photoshop 7.8 -2022-05-06
CVE-2022-1516 Linux kernel 代码问题漏洞 — Kernel 5.5 -2022-05-05
CVE-2021-3750 QEMU 资源管理错误漏洞 — QEMU 8.2 -2022-05-02
CVE-2022-1114 Imagemagick Studio ImageMagick 资源管理错误漏洞 — ImageMagick 7.1 -2022-04-29

Vulnerabilities classified as CWE-416 (释放后使用) represent 2577 CVEs. The CWE taxonomy describes the weakness; review individual CVEs for product-specific impact.