#VU55920 Heap-based buffer overflow in Exiv2 - CVE-2021-29457

Vulnerability identifier: #VU55920

Vulnerability risk: Medium

CVSSv4.0: 4.8 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2021-29457

CWE-ID: N/A

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Exiv2
Universal components / Libraries / Libraries used by multiple products

Vendor: GNU

Description

The vulnerability allows a remote attacker to execute arbitrary code on the target system.

The vulnerability exists due to a boundary error. A remote attacker can trick the victim top open a specially crafted image, trigger a heap-based buffer overflow and execute arbitrary code on the target system.

Note that this bug is only triggered when _writing_ the metadata, which is a less frequently used Exiv2 operation than _reading_ the metadata. For example, to trigger the bug in the Exiv2 command-line application, you need to add an extra command-line argument such as `insert`.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Exiv2: 0.16 - 0.27.3

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External links
https://github.com/Exiv2/exiv2/issues/1529
https://github.com/Exiv2/exiv2/pull/1534
https://github.com/Exiv2/exiv2/security/advisories/GHSA-v74w-h496-cgqm
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/2XQT5F5IINTDYDAFGVGQZ7PMMLG7I5ZZ/
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/P2A5GMJEXQ5Q76JK6F6VKK5JYCLVFGKN/

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.