OpenSSL up to 3.3.1 Client Protocol SSL_select_next_proto client/client_len memory corruption

Summaryinfo

A vulnerability labeled as critical has been found in OpenSSL up to 3.3.1. Affected is the function SSL_select_next_proto of the component Client Protocol Handler. Executing a manipulation of the argument client/client_len can lead to memory corruption. This vulnerability appears as CVE-2024-5535. The attack may be performed from remote. There is no available exploit. The affected component should be upgraded.

Detailsinfo

A vulnerability was found in OpenSSL up to 3.3.1. It has been declared as critical. This vulnerability affects the function SSL_select_next_proto of the component Client Protocol Handler. The manipulation of the argument client/client_len with an unknown input leads to a memory corruption vulnerability. The CWE definition for the vulnerability is CWE-119. The product performs operations on a memory buffer, but it can read from or write to a memory location that is outside of the intended boundary of the buffer. As an impact it is known to affect confidentiality, integrity, and availability. CVE summarizes:

Issue summary: Calling the OpenSSL API function SSL_select_next_proto with an empty supported client protocols buffer may cause a crash or memory contents to be sent to the peer. Impact summary: A buffer overread can have a range of potential consequences such as unexpected application beahviour or a crash. In particular this issue could result in up to 255 bytes of arbitrary private data from memory being sent to the peer leading to a loss of confidentiality. However, only applications that directly call the SSL_select_next_proto function with a 0 length list of supported client protocols are affected by this issue. This would normally never be a valid scenario and is typically not under attacker control but may occur by accident in the case of a configuration or programming error in the calling application. The OpenSSL API function SSL_select_next_proto is typically used by TLS applications that support ALPN (Application Layer Protocol Negotiation) or NPN (Next Protocol Negotiation). NPN is older, was never standardised and is deprecated in favour of ALPN. We believe that ALPN is significantly more widely deployed than NPN. The SSL_select_next_proto function accepts a list of protocols from the server and a list of protocols from the client and returns the first protocol that appears in the server list that also appears in the client list. In the case of no overlap between the two lists it returns the first item in the client list. In either case it will signal whether an overlap between the two lists was found. In the case where SSL_select_next_proto is called with a zero length client list it fails to notice this condition and returns the memory immediately following the client list pointer (and reports that there was no overlap in the lists). This function is typically called from a server side application callback for ALPN or a client side application callback for NPN. In the case of ALPN the list of protocols supplied by the client is guaranteed by libssl to never be zero in length. The list of server protocols comes from the application and should never normally be expected to be of zero length. In this case if the SSL_select_next_proto function has been called as expected (with the list supplied by the client passed in the client/client_len parameters), then the application will not be vulnerable to this issue. If the application has accidentally been configured with a zero length server list, and has accidentally passed that zero length server list in the client/client_len parameters, and has additionally failed to correctly handle a "no overlap" response (which would normally result in a handshake failure in ALPN) then it will be vulnerable to this problem. In the case of NPN, the protocol permits the client to opportunistically select a protocol when there is no overlap. OpenSSL returns the first client protocol in the no overlap case in support of this. The list of client protocols comes from the application and should never normally be expected to be of zero length. However if the SSL_select_next_proto function is accidentally called with a client_len of 0 then an invalid memory pointer will be returned instead. If the application uses this output as the opportunistic protocol then the loss of confidentiality will occur. This issue has been assessed as Low severity because applications are most likely to be vulnerable if they are using NPN instead of ALPN - but NPN is not widely used. It also requires an application configuration or programming error. Finally, this issue would not typically be under attacker control making active exploitation unlikely. The FIPS modules in 3.3, 3.2, 3.1 and 3.0 are not affected by this issue. Due to the low severity of this issue we are not issuing new releases of OpenSSL at this time. The fix will be included in the next releases when they become available.

The weakness was presented by Joseph Birr-pixton. The advisory is available at openssl.org. This vulnerability was named CVE-2024-5535 since 05/30/2024. The exploitation appears to be easy. The attack can be initiated remotely. No form of authentication is required for a successful exploitation. Technical details are known, but there is no available exploit. The structure of the vulnerability defines a possible price range of USD $5k-$25k at the moment (estimation calculated on 06/22/2026).

The vulnerability scanner Nessus provides a plugin with the ID 208438 (RHEL 8 : openssl (RHSA-2024:7846)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 1.0.2zk, 1.1.1za, 3.0.15, 3.1.7, 3.2.3 or 3.3.2 eliminates this vulnerability. The upgrade is hosted for download at github.openssl.org. Applying the patch 9947251413065a05189a63c9b7a6c1d4e224c21c is able to eliminate this problem. The bugfix is ready for download at github.openssl.org. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the databases at Tenable (208438) and CERT Bund (WID-SEC-2024-1469). If you want to get best quality of vulnerability data, you may have to visit VulDB.

Affected

• IBM VIOS
• IBM AIX
• Debian Linux
• Amazon Linux 2
• IBM InfoSphere Information Server
• Red Hat Enterprise Linux
• Fedora Linux
• Ubuntu Linux
• Xerox FreeFlow Print Server
• SUSE Linux
• Oracle Linux
• NetApp FAS
• NetApp AFF
• IBM Power Hardware Management Console
• Dell PowerEdge
• IBM Security Guardium
• NetApp ActiveIQ Unified Manager
• Dell BIOS
• Open Source OpenSSL
• IBM MQ
• Dell Computer
• IBM App Connect Enterprise
• IBM Rational Build Forge
• IBM QRadar SIEM
• Hitachi Ops Center
• Insyde UEFI Firmware
• HPE HP-UX
• Red Hat OpenShift
• SolarWinds Platform
• IBM Rational ClearCase
• IBM Rational ClearQuest
• Red Hat JBoss Core Services
• IBM Spectrum Protect Plus
• IBM Storage Scale System
• Dell PowerProtect Data Domain
• Dell PowerProtect Data Domain Management Center
• Dell PowerProtect Data Domain OS
• Dell NetWorker
• Dell PowerScale OneFS
• IBM Cognos Analytics

Productinfo

Type

• Network Encryption Software

Name

• OpenSSL

Version

• 1.0.2za
• 1.0.2zb
• 1.0.2zc
• 1.0.2zd
• 1.0.2ze
• 1.0.2zf
• 1.0.2zg
• 1.0.2zh
• 1.0.2zi
• 1.0.2zj
• 1.1.1a
• 1.1.1b
• 1.1.1c
• 1.1.1d
• 1.1.1e
• 1.1.1f
• 1.1.1g
• 1.1.1h
• 1.1.1i
• 1.1.1j
• 1.1.1k
• 1.1.1l
• 1.1.1m
• 1.1.1n
• 1.1.1o
• 1.1.1p
• 1.1.1q
• 1.1.1r
• 1.1.1s
• 1.1.1t
• 1.1.1u
• 1.1.1v
• 1.1.1w
• 1.1.1x
• 1.1.1y
• 1.1.1z
• 3.0.0
• 3.0.1
• 3.0.2
• 3.0.3
• 3.0.4
• 3.0.5
• 3.0.6
• 3.0.7
• 3.0.8
• 3.0.9
• 3.0.10
• 3.0.11
• 3.0.12
• 3.0.13
• 3.0.14
• 3.1.0
• 3.1.1
• 3.1.2
• 3.1.3
• 3.1.4
• 3.1.5
• 3.1.6
• 3.2.0
• 3.2.1
• 3.2.2
• 3.3.0
• 3.3.1

License

• open-source

Website

• Product: https://www.openssl.org/

CPE 2.3info

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CPE 2.2info

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Entryinfo

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