OP-TEE OS through 4.10.0, fixed in commit 8794043, contains a use-after-free vulnerability in the Trusted Application loader that allows attackers with the ability to load a signed Trusted Application to corrupt secure-world kernel memory by setting the TAFLAGCONCURRENT flag in a user TA signed header. Attackers can cause two concurrent sessions to operate on the same shared context without locking, corrupting the uctx->vminfo.regions list during memref parameter mapping and unmapping to free vmregion nodes still in use, resulting in a use-after-free in S-EL1 secure-world kernel memory.

OP-TEE OS through 4.10.0, fixed in commit 7b8b494, contains a buffer underwrite vulnerability in the RSA NOPAD encrypt and decrypt operations within the mbedTLS software backend and SE050 hardware driver that allows a malicious Trusted Application to corrupt secure-world heap memory by supplying an input length exceeding the RSA modulus size. When srclen exceeds rsalen, the subtraction expression wraps to a large unsigned value, causing a subsequent memcpy to write attacker-controlled data before the destination buffer in S-EL1 secure-world heap memory.

OP-TEE is a Trusted Execution Environment (TEE) designed as companion to a non-secure Linux kernel running on Arm; Cortex-A cores using the TrustZone technology. Prior to version 4.11.0, on many of the ECDH shared secret paths, the public key isn't verified to be a point on the correct curve. By passing approximately 30-40 crafted public keys to OP-TEE, the private key can be reconstructed by a normal world attacker. When calling TEEDeriveKey the public key is provided with full X and Y values, but the (X, Y) point might not satisfy the Y^2 == X^3 + aX + b mod P math for the specific curve that is used. When those public keys aren't rejected, the attacker can select public keys such that each DeriveKey call will leak d % r where d is the private key and r comes from the relationship between the correct curve and the attacker selected curve. With enough leaked data the Chinese remainder theorem can be used to recover the full private key. Version 4.11.0 fixes the issue.

OP-TEE is a Trusted Execution Environment (TEE) designed as companion to a non-secure Linux kernel running on Arm; Cortex-A cores using the TrustZone technology. Starting in version 4.3.0 and prior to version 4.11.0, a type confusion vulnerability exists in OP-TEE OS when processing an FFAMEMSHARE request from the normal world. This only applies when OP-TEE is configured as an SPMC for S-EL0 SPs, that is, with CFGCORESEL1SPMC=y and CFGSECUREPARTITION=y. Version 4.11.0 fixes the issue.

OP-TEE is a Trusted Execution Environment (TEE) designed as companion to a non-secure Linux kernel running on Arm; Cortex-A cores using the TrustZone technology. Starting in version 3.16.0 and prior to 4.11.0, a user-after-free (UAF) race condition exists in the shared memory teardown logic of FF-A within OP-TEE SPMC/SP flows. This only applies when OP-TEE is configured as an SPMC for S-EL0 SPs, that is, with CFGSECUREPARTITION=y. The function spmemremove(), responsible for freeing entries in smem->receivers and smem->regions, fails to acquire the global spmemlock before performing the free() operations. Concurrently, other code paths, such as spmemgetreceiver(), iterate over these same lists without holding a lock, or, like spmemisshared(), iterate while holding the lock but are not serialized against the unprotected free() in spmemremove(). This creates a cross-thread race where a thread iterating the list can acquire a pointer to an entry (e.g., struct spmemmapregion or struct spmemreceiver), and then another thread calls spmemremove(), freeing the object. When the first thread resumes and dereferences the pointer, it results in a Use-After-Free vulnerability. Version 4.11.0 fixes the issue.

OP-TEE is a Trusted Execution Environment (TEE) designed as companion to a non-secure Linux kernel running on Arm; Cortex-A cores using the TrustZone technology. Starting in version 3.21.0 and prior to version 4.11.0, the ARM Crypto Extensions accelerated SHA-3 implementation has an off-by-one error that can cause a massive heap overflow that corrupts all TEE kernel memory following the hash state. This affects all platforms built with CFGCRYPTOWITHCE82=y (ARMv8.2+ with SHA3 Crypto Extensions). Version 4.11.0 contains a patch. As a workaround, disable SHA3 Crypto Extensions with CFGCRYPTOWITHCE82=n.

OP-TEE is a Trusted Execution Environment (TEE) designed as companion to a non-secure Linux kernel running on Arm; Cortex-A cores using the TrustZone technology. Starting in version 4.5.0 and prior to version 4.11.0, the RSA PKCS#1 v1.5 decryption implementation in the Hisilicon HPRE crypto driver uses non-constant-time memcmp() for label hash verification and has multiple distinguishable error paths. This creates a Bleichenbacher-style padding oracle that allows an attacker to recover RSA PKCS#1 v1.5 plaintext. Version 4.11.0 contains a patch. As a workaround, disable Hisilicon HPRE RSA driver with CFGHISILICONACCV3=n.

OP-TEE is a Trusted Execution Environment (TEE) designed as companion to a non-secure Linux kernel running on Arm; Cortex-A cores using the TrustZone technology. Starting in version 3.3.0 and prior to version 4.11.0, a resource leak exists in OP-TEE’s shared memory cleanup logic because the function cleanupshmrefs() in core/tee/entrystd.c fails to apply a required bitmask (OPTEEMSGATTRTYPEMASK) to parameter attributes. When processing non-contiguous memory parameters from a normal-world caller, the system fails to match the attribute type in its internal switch statement and skips the necessary mobjput() call. This results in a persistent reference leak of mobjregshm objects, which remain on internal lists with dangling refcounts. This affects non-FF-A configurations that support non-contiguous, non-secure shared memory. Over time, these accumulated leaks progressively consume the secure-world heap, degrading the system's ability to service trusted application operations and eventually requiring a reboot to recover. Version 4.11.0 contains a patch. No known workarounds are available.

OP-TEE is a Trusted Execution Environment (TEE) designed as companion to a non-secure Linux kernel running on Arm; Cortex-A cores using the TrustZone technology. Starting in version 3.20.0 and prior to version 4.11.0, a vulnerability in OP-TEE’s subkey rollback protection allows the use of revoked or older subkey versions because the system fails to propagate versioning data during the Trusted Application (TA) loading process. In core/crypto/signedhdr.c, the function shdrloadpubkey() parses subkey headers but does not assign the subkeyversion to the runtime shdrpubkey structure. As a result, the key->version field remains at zero regardless of the version specified in the header. When reefstaopen() in core/kernel/reefsta.c calls checkupdateversion(), it passes this zeroed version to the rollback database. Because the database never receives a non-zero version to record, it never advances, effectively bypassing the rollback check and allowing TAs signed with downgraded subkey chains to load successfully. This impacts OP-TEE mainline configurations that utilize subkey-based signing chains for Trusted Application (TA) authentication. Version 4.11.0 contains a patch. No known workarounds are available.

OP-TEE is a Trusted Execution Environment (TEE) designed as companion to a non-secure Linux kernel running on Arm; Cortex-A cores using the TrustZone technology. Starting in version 3.9.0 and prior to version 4.11.0, the RSA-OAEP decryption implementation in the NXP CAAM crypto driver uses non-constant-time memcmp() for label hash verification and has multiple distinguishable error paths. This creates a Manger-style padding oracle that allows an attacker to recover RSA-OAEP plaintext with approximately 1000-2000 adaptive chosen ciphertext queries. Version 4.11.0 contains a patch. As a workaround, disable the NXP CAAM RSA driver with CFGCRYPTODRVRSA=n.

OP-TEE is a Trusted Execution Environment (TEE) designed as companion to a non-secure Linux kernel running on Arm; Cortex-A cores using the TrustZone technology. Starting in version 3.0.0 and prior to version 4.11.0, 32-bit integer overflows in OP-TEE core's AES-GCM implementation cause the authentication tag to be computed with incorrect bit-length values after processing more than 512 megabytes of payload or Additional Authenticated Data (AAD). Version 4.11.0 contains a patch. No known workarounds are available.

OP-TEE is a Trusted Execution Environment (TEE) designed as companion to a non-secure Linux kernel running on Arm; Cortex-A cores using the TrustZone technology. Starting in version 3.10.0 and prior to version 4.11.0, an unbounded recursion can crash the PKCS#11 TA. Version 4.11.0 contains a patch. No known workarounds are available.

OP-TEE is a Trusted Execution Environment (TEE) designed as companion to a non-secure Linux kernel running on Arm; Cortex-A cores using the TrustZone technology. Starting in version 4.5.0 and prior to version 4.11.0, the RSA-OAEP decryption implementation in the Hisilicon HPRE crypto driver uses non-constant-time memcmp() for label hash verification and has multiple distinguishable error paths. This creates a Manger-style padding oracle that allows an attacker to recover RSA-OAEP plaintext with approximately 1000-2000 adaptive chosen ciphertext queries. Only affects plat-d06 with CFGHISILICONACCV3=y, which seems to be disabled by default. Version 4.11.0 contains a patch. As a workaround, disable Hisilicon HPRE RSA driver with CFGHISILICONACCV3=n.

OP-TEE Trusted OS is the secure side implementation of OP-TEE project, a Trusted Execution Environment. Versions prior to 3.19.0, contain an Improper Validation of Array Index vulnerability. The function cleanupshmrefs() is called by both entryinvokecommand() and entryopensession(). The commands OPTEEMSGCMDOPENSESSION and OPTEEMSGCMDINVOKECOMMAND can be executed from the normal world via an OP-TEE SMC. This function is not validating the numparams argument, which is only limited to OPTEEMSGMAXNUMPARAMS (127) in the function getcmdbuffer(). Therefore, an attacker in the normal world can craft an SMC call that will cause out-of-bounds reading in cleanupshmrefs and potentially freeing of fake-objects in the function mobjput(). A normal-world attacker with permission to execute SMC instructions may exploit this flaw. Maintainers believe this problem permits local privilege escalation from the normal world to the secure world. Version 3.19.0 contains a fix for this issue. There are no known workarounds.

It has been reported that libtomcrypt may be vulnerable to a Bleichenbacher attack due to a vulnerability in rsaverifyhash.c

CERT has provided the details from Intel Security Advanced Threat Research team. ---------------------------------------------------------------------- Bleichenbacher signature forgery attack in OP-TEE Background The implementation for RSA signature verification of PKCS 1 v1.5 in the Open Portable Trusted Execution Environment (https://github.com/OP-TEE/opteeos) appears to be vulnerable to a Bleichenbacher signature forgery attack. The vulnerability may result in RSA signature or public certificate forgery when a low public exponent (for example, e = 3) is used. Vulnerability The function rsaverifyhashex (https://github.com/OPTEE/opteeos/blob/master/core/lib/libtomcrypt/src/pk/rsa/rsaverifyhash.c) does not check the number of remaining bytes in the decrypted message after ASN.1 encoded data. The function decodes the ASN.1 message and checks that it has the correct structure and values (OID and hash). This permits additional data after the ASN.1 message that can be used to forge a PKCS1 v1.5 signature for keys with a low public exponent. The original variant of the attack is described here: https://www.ietf.org/mail-archive/web/openpgp/current/msg00999.html

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OP-TEE is a Trusted Execution Environment (TEE) designed as companion to a non-secure Linux kernel running on Arm; Cortex-A cores using the TrustZone technology. From 3.8.0 to 4.10, in the function emsapkcs1v15encode() in core/drivers/crypto/cryptoapi/acipher/rsassa.c, the amount of padding needed, "PS size", is calculated by subtracting the size of the digest and other fields required for the EMA-PKCS1-v15 encoding from the size of the modulus of the key. By selecting a small enough modulus, this subtraction can overflow. The padding is added as a string of 0xFF bytes with a call to memset(), and an underflowed integer will cause the memset() call to overwrite until OP-TEE crashes. This only affects platforms registering RSA acceleration.

OP-TEE is a Trusted Execution Environment (TEE) designed as companion to a non-secure Linux kernel running on Arm; Cortex-A cores using the TrustZone technology. In versions 3.13.0 through 4.10.0, missing checks in entrygetattributevalue() in ta/pkcs11/src/object.c can lead to out-of-bounds read from the PKCS#11 TA heap or a crash. When chained with the OOB read, the PKCS#11 TA function PKCS11CMDGETATTRIBUTEVALUE or entrygetattributevalue() can, with a bad template parameter, be tricked into reading at most 7 bytes beyond the end of the template buffer and writing beyond the end of the template buffer with the content of an attribute value of a PKCS#11 object. Commits e031c4e562023fd9f199e39fd2e85797e4cbdca9, 16926d5a46934c46e6656246b4fc18385a246900, and 149e8d7ecc4ef8bb00ab4a37fd2ccede6d79e1ca contain patches and are anticipated to be part of version 4.11.0.

OP-TEE is a Trusted Execution Environment (TEE) designed as companion to a non-secure Linux kernel running on Arm; Cortex-A cores using the TrustZone technology. In version 4.5.0, using a specially crafted tee-supplicant binary running in REE userspace, an attacker can trigger a panic in a TA that uses the libutee Secure Storage API. Many functions in libutee, specifically those which make up the Secure Storage API, will panic if a system call returns an unexpected return code. This behavior is mandated by the TEE Internal Core API specification. However, in OP-TEE’s implementation, return codes of secure storage operations are passed through unsanitized from the REE tee-supplicant, through the Linux kernel tee-driver, through the OP-TEE kernel, back to libutee. Thus, an attacker with access to REE userspace, and the ability to stop tee-supplicant and replace it with their own process (generally trivial for a root user, and depending on the way permissions are set up, potentially available even to less privileged users) can run a malicious tee-supplicant process that responds to storage requests with unexpected response codes, triggering a panic in the requesting TA. This is particularly dangerous for TAs built with TAFLAGSINGLEINSTANCE (corresponding to gpd.ta.singleInstance and TAFLAGINSTANCEKEEPALIVE (corresponding to gpd.ta.keepAlive). The behavior of these TAs may depend on memory that is preserved between sessions, and the ability of an attacker to panic the TA and reload it with a clean memory space can compromise the behavior of those TAs. A critical example of this is the opteeftpm TA. It uses the kept alive memory to hold PCR values, which crucially must be non-resettable. An attacker who can trigger a panic in the fTPM TA can reset the PCRs, and then extend them PCRs with whatever they choose, falsifying boot measurements, accessing sealed data, and potentially more. The impact of this issue depends significantly on the behavior of affected TAs. For some, it could manifest as a denial of service, while for others, like the fTPM TA, it can result in the disclosure of sensitive data. Anyone running the fTPM TA is affected, but similar attacks may be possible on other TAs that leverage the Secure Storage API. A fix is available in commit 941a58d78c99c4754fbd4ec3079ec9e1d596af8f.

It has been reported that libtomcrypt may be vulnerable to a Bleichenbacher attack due to a vulnerability in rsaverifyhash.c

CERT has provided the details from Intel Security Advanced Threat Research team. ---------------------------------------------------------------------- Bleichenbacher signature forgery attack in OP-TEE Background The implementation for RSA signature verification of PKCS 1 v1.5 in the Open Portable Trusted Execution Environment (https://github.com/OP-TEE/opteeos) appears to be vulnerable to a Bleichenbacher signature forgery attack. The vulnerability may result in RSA signature or public certificate forgery when a low public exponent (for example, e = 3) is used. Vulnerability The function rsaverifyhashex (https://github.com/OPTEE/opteeos/blob/master/core/lib/libtomcrypt/src/pk/rsa/rsaverifyhash.c) does not check the number of remaining bytes in the decrypted message after ASN.1 encoded data. The function decodes the ASN.1 message and checks that it has the correct structure and values (OID and hash). This permits additional data after the ASN.1 message that can be used to forge a PKCS1 v1.5 signature for keys with a low public exponent. The original variant of the attack is described here: https://www.ietf.org/mail-archive/web/openpgp/current/msg00999.html

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