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Unrated severityNVD Advisory· Published Feb 8, 2021· Updated Aug 3, 2024

CVE-2021-26222

CVE-2021-26222

Description

The ezxml_new function in ezXML 0.8.6 and earlier is vulnerable to OOB write when opening XML file after exhausting the memory pool.

AI Insight

LLM-synthesized narrative grounded in this CVE's description and references.

ezXML 0.8.6 and earlier has an out-of-bounds write in ezxml_new() due to unchecked malloc return, causing crashes or potential memory corruption.

Vulnerability

The vulnerability resides in ezxml_new() (ezxml.c line 843) of ezXML library versions 0.8.6 and earlier. When opening a specially crafted XML file, repeated memory allocations can exhaust the memory pool. The function does not properly check the return value of malloc(), leading to a null or invalid pointer being used in subsequent operations. This causes an out-of-bounds (OOB) write. The affected code path is reachable during XML parsing when memory pressure is high [1].

Exploitation

An attacker needs to provide a crafted XML file that triggers excessive memory allocations, depleting available memory. This can be achieved locally or remotely if the application processes user-supplied or networked XML files. The exploit sequence involves parsing the XML file while the system’s memory pool is exhausted; malloc() returns NULL, and ezxml_new() fails to check this, resulting in a write to an invalid address [1].

Impact

Successful exploitation leads to an out-of-bounds write. In environments with strict memory protection, this results in a segmentation fault (DoS). In systems with limited memory restrictions (e.g., embedded devices), the attacker may achieve a near-NULL pointer overwrite, potentially enabling arbitrary write or privilege escalation depending on memory layout [1].

Mitigation

No official patch or fixed version has been released as of the publication date (2021-02-08). The bug tracker report (status: open) indicates the issue remains unfixed [1]. Users should consider avoiding processing untrusted XML files with vulnerable ezXML versions or applying memory protection mechanisms (e.g., ASLR, guard pages) to reduce impact. Until a patch is available, no direct workaround exists in the library itself.

References
  1. ezXML / Bugs / #22 Out-of-bounds write caused by incorrect error handling of malloc in ezxml_new (ezxml.c:843)

AI Insight generated on May 27, 2026. Synthesized from this CVE's description and the cited reference URLs; citations are validated against the source bundle.

Affected products

59

Patches

0

No patches discovered yet.

Vulnerability mechanics

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References

1

News mentions

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