OpenSSL up to 3.4.3/3.5.4/3.6.0 PKCS#12 File out-of-bounds write

Summaryinfo

A vulnerability was found in OpenSSL up to 3.4.3/3.5.4/3.6.0. It has been rated as critical. This affects an unknown function of the component PKCS#12 File Handler. This manipulation causes out-of-bounds write. This vulnerability is handled as CVE-2025-11187. The attack can be initiated remotely. There is not any exploit available. Upgrading the affected component is advised.

Detailsinfo

A vulnerability has been found in OpenSSL up to 3.4.3/3.5.4/3.6.0 and classified as critical. Affected by this vulnerability is an unknown function of the component PKCS#12 File Handler. The manipulation with an unknown input leads to a out-of-bounds write vulnerability. The CWE definition for the vulnerability is CWE-787. The product writes data past the end, or before the beginning, of the intended buffer. As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:

Issue summary: PBMAC1 parameters in PKCS#12 files are missing validation which can trigger a stack-based buffer overflow, invalid pointer or NULL pointer dereference during MAC verification. Impact summary: The stack buffer overflow or NULL pointer dereference may cause a crash leading to Denial of Service for an application that parses untrusted PKCS#12 files. The buffer overflow may also potentially enable code execution depending on platform mitigations. When verifying a PKCS#12 file that uses PBMAC1 for the MAC, the PBKDF2 salt and keylength parameters from the file are used without validation. If the value of keylength exceeds the size of the fixed stack buffer used for the derived key (64 bytes), the key derivation will overflow the buffer. The overflow length is attacker-controlled. Also, if the salt parameter is not an OCTET STRING type this can lead to invalid or NULL pointer dereference. Exploiting this issue requires a user or application to process a maliciously crafted PKCS#12 file. It is uncommon to accept untrusted PKCS#12 files in applications as they are usually used to store private keys which are trusted by definition. For this reason the issue was assessed as Moderate severity. The FIPS modules in 3.6, 3.5 and 3.4 are not affected by this issue, as PKCS#12 processing is outside the OpenSSL FIPS module boundary. OpenSSL 3.6, 3.5 and 3.4 are vulnerable to this issue. OpenSSL 3.3, 3.0, 1.1.1 and 1.0.2 are not affected by this issue as they do not support PBMAC1 in PKCS#12.

The advisory is shared at openssl-library.org. This vulnerability is known as CVE-2025-11187 since 09/30/2025. The exploitation appears to be easy. The attack can be launched remotely. The exploitation doesn't need any form of authentication. Neither technical details nor an exploit are publicly available. The price for an exploit might be around USD $5k-$25k at the moment (estimation calculated on 06/09/2026).

The vulnerability scanner Nessus provides a plugin with the ID 297022 (RHEL 9 : openssl (RHSA-2026:1473)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 3.4.4, 3.5.5 or 3.6.1 eliminates this vulnerability.

The vulnerability is also documented in the databases at Tenable (297022) and CERT Bund (WID-SEC-2026-0234). If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Affected

• IBM VIOS
• IBM AIX
• Debian Linux
• Google Cloud Platform
• IBM DataPower Gateway
• Amazon Linux 2
• Red Hat Enterprise Linux
• NetApp Data ONTAP
• Siemens SIMATIC WinCC
• Ubuntu Linux
• SUSE Linux
• Oracle Linux
• IGEL OS
• IBM QRadar SIEM
• SUSE openSUSE
• Fabasoft Cloud
• RESF Rocky Linux
• IBM App Connect Enterprise
• Dell BIOS
• Dell PowerScale OneFS
• Siemens SIMATIC STEP 7
• Open Source OpenSSL
• Broadcom Brocade SANnav
• Fortinet FortiPortal
• Meinberg LANTIME
• Red Hat OpenShift
• IBM MQ
• Open Source Camunda
• ABB AC-500
• Dell Secure Connect Gateway
• IBM InfoSphere Information Server
• Splunk Splunk Enterprise
• Phoenix Contact FL MGUARD
• Phoenix Contact FL SWITCH
• Phoenix Contact TC ROUTER
• Dell integrated Dell Remote Access Controller
• Siemens SIMATIC S7
• Insyde UEFI Firmware
• NCP Secure Enterprise VPN Server

Productinfo

Type

• Network Encryption Software

Name

• OpenSSL

Version

• 3.0
• 3.1
• 3.2
• 3.3
• 3.4
• 3.4.0
• 3.4.1
• 3.4.2
• 3.4.3
• 3.5
• 3.5.0
• 3.5.1
• 3.5.2
• 3.5.3
• 3.5.4
• 3.6.0

License

• open-source

Website

• Product: https://www.openssl.org/

CPE 2.3info

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Entryinfo

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