gRPC contains a vulnerability that allows hpack table accounting errors could lead to unwanted disconnects between clients and servers in exceptional cases/ Three vectors were found that allow the following DOS attacks: - Unbounded memory buffering in the HPACK parser - Unbounded CPU consumption in the HPACK parser The unbounded CPU consumption is down to a copy that occurred per-input-block in the parser, and because that could be unbounded due to the memory copy bug we end up with an O(n^2) parsing loop, with n selected by the client. The unbounded memory buffering bugs: - The header size limit check was behind the string reading code, so we needed to first buffer up to a 4 gigabyte string before rejecting it as longer than 8 or 16kb. - HPACK varints have an encoding quirk whereby an infinite number of 0’s can be added at the start of an integer. gRPC’s hpack parser needed to read all of them before concluding a parse. - gRPC’s metadata overflow check was performed per frame, so that the following sequence of frames could cause infinite buffering: HEADERS: containing a: 1 CONTINUATION: containing a: 2 CONTINUATION: containing a: 3 etc…

The remote SUSE Linux SLED15 / SLED_SAP15 / SLES15 / SLES_SAP15 host has packages installed that are affected by a vulnerability as referenced in the SUSE-SU-2026:0840-1 advisory.

    This update for grpc fixes the following issue:

    - CVE-2023-33953: unbounded memory and CPU consumption in the HPACK parser leads to remote DoS     (bsc#1214148).

Tenable has extracted the preceding description block directly from the SUSE security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

  - gRPC contains a vulnerability that allows hpack table accounting errors could lead to unwanted disconnects     between clients and servers in exceptional cases/ Three vectors were found that allow the following DOS     attacks: - Unbounded memory buffering in the HPACK parser - Unbounded CPU consumption in the HPACK parser     The unbounded CPU consumption is down to a copy that occurred per-input-block in the parser, and because     that could be unbounded due to the memory copy bug we end up with an O(n^2) parsing loop, with n selected     by the client. The unbounded memory buffering bugs: - The header size limit check was behind the string     reading code, so we needed to first buffer up to a 4 gigabyte string before rejecting it as longer than 8     or 16kb. - HPACK varints have an encoding quirk whereby an infinite number of 0's can be added at the     start of an integer. gRPC's hpack parser needed to read all of them before concluding a parse. - gRPC's     metadata overflow check was performed per frame, so that the following sequence of frames could cause     infinite buffering: HEADERS: containing a: 1 CONTINUATION: containing a: 2 CONTINUATION: containing a: 3     etc (CVE-2023-33953)

Note that Nessus relies on the presence of the package as reported by the vendor.

The version of Tencent Linux installed on the remote TencentOS Server 4 host is prior to tested version. It is, therefore, affected by a vulnerability as referenced in the TSSA-2025:0125 advisory.

    Package updates are available for TencentOS Server 4 that fix the following vulnerabilities:

    CVE-2023-33953:
    gRPC contains a vulnerability that allows hpack table accounting errors could lead to unwanted disconnects     between clients and servers in exceptional cases/Three vectors were found that allow the following DOS     attacks:

    - Unbounded memory buffering in the HPACK parser
    - Unbounded CPU consumption in the HPACK parser

    The unbounded CPU consumption is down to a copy that occurred per-input-block in the parser, and because     that could be unbounded due to the memory copy bug we end up with an O(n^2) parsing loop, with n selected     by the client.

    The unbounded memory buffering bugs:

    - The header size limit check was behind the string reading code, so we needed to first buffer up to a 4     gigabyte string before rejecting it as longer than 8 or 16kb.
    - HPACK varints have an encoding quirk whereby an infinite number of 0s can be added at the start of an     integer. gRPCs hpack parser needed to read all of them before concluding a parse.
    - gRPCs metadata overflow check was performed per frame, so that the following sequence of frames could     cause infinite buffering: HEADERS: containing a: 1 CONTINUATION: containing a: 2 CONTINUATION: containing     a: 3 etc

Tenable has extracted the preceding description block directly from the Tencent Linux security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

There are packages installed that are affected by a vulnerability referenced in the following CVE:

  - gRPC contains a vulnerability that allows hpack table accounting errors could lead to unwanted disconnects
    between clients and servers in exceptional cases/ Three vectors were found that allow the following DOS
    attacks: - Unbounded memory buffering in the HPACK parser - Unbounded CPU consumption in the HPACK parser
    The unbounded CPU consumption is down to a copy that occurred per-input-block in the parser, and because
    that could be unbounded due to the memory copy bug we end up with an O(n^2) parsing loop, with n selected
    by the client. The unbounded memory buffering bugs: - The header size limit check was behind the string
    reading code, so we needed to first buffer up to a 4 gigabyte string before rejecting it as longer than 8
    or 16kb. - HPACK varints have an encoding quirk whereby an infinite number of 0’s can be added at the
    start of an integer. gRPC’s hpack parser needed to read all of them before concluding a parse. - gRPC’s
    metadata overflow check was performed per frame, so that the following sequence of frames could cause
    infinite buffering: HEADERS: containing a: 1 CONTINUATION: containing a: 2 CONTINUATION: containing a: 3
    etc… (CVE-2023-33953)

The version of Oracle Business Intelligence Enterprise Edition (OAS) 7.0.0.0 installed on the remote host is affected by multiple vulnerabilities as referenced in the January 2025 CPU advisory, including the following:

  - Vulnerability in the Oracle Business Intelligence Enterprise Edition product of Oracle Analytics     (component: Analytics Server (SciPy)). Supported versions that are affected are 7.0.0.0.0 and 7.6.0.0.0.     Easily exploitable vulnerability allows unauthenticated attacker with network access via HTTP to     compromise Oracle Business Intelligence Enterprise Edition. Successful attacks of this vulnerability can     result in takeover of Oracle Business Intelligence Enterprise Edition. (CVE-2023-29824)

  - Vulnerability in the Oracle Business Intelligence Enterprise Edition product of Oracle Analytics     (component: Platform Security (OpenSSL)). Supported versions that are affected are 7.0.0.0.0, 7.6.0.0.0     and 12.2.1.4.0. Easily exploitable vulnerability allows unauthenticated attacker with network access via     TLS to compromise Oracle Business Intelligence Enterprise Edition. Successful attacks of this     vulnerability can result in unauthorized access to critical data or complete access to all Oracle Business     Intelligence Enterprise Edition accessible data and unauthorized ability to cause a hang or frequently     repeatable crash (complete DOS) of Oracle Business Intelligence Enterprise Edition. (CVE-2024-5535)

  - Vulnerability in the Oracle Business Intelligence Enterprise Edition product of Oracle Analytics     (component: Analytics Server, Pipeline Test Failures, Installation (Spring Framework)). Supported versions     that are affected are 7.0.0.0.0, 7.6.0.0.0 and 12.2.1.4.0. Easily exploitable vulnerability allows     unauthenticated attacker with network access via HTTP to compromise Oracle Business Intelligence     Enterprise Edition. Successful attacks of this vulnerability can result in unauthorized ability to cause     a partial denial of service (partial DOS) of Oracle Business Intelligence Enterprise Edition.     (CVE-2024-38809)

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The remote Redhat Enterprise Linux 9 host has a package installed that is affected by multiple vulnerabilities as referenced in the RHSA-2024:10761 advisory.

    Python-based worker for Red Hat connect, used to launch Ansible playbooks via Ansible Runner.

    Security Fix(es):

    * python-wheel: remote attackers can cause denial of service via attacker controlled input to wheel cli     (CVE-2022-40898)

    * gRPC: sensitive information disclosure (CVE-2023-32731)

    * gRPC: Reachable Assertion (CVE-2023-1428)

    * gRPC: hpack table accounting errors can lead to denial of service (CVE-2023-33953)

    For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and     other related information, refer to the CVE page(s) listed in the References section.

Tenable has extracted the preceding description block directly from the Red Hat Enterprise Linux security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

An update of the grpc package has been released.

According to the versions of the grpc package installed, the EulerOS installation on the remote host is affected by the following vulnerabilities :

  - gRPC contains a vulnerability that allows hpack table accounting errors could lead to unwanted disconnects     between clients and servers in exceptional cases/ Three vectors were found that allow the following DOS     attacks: - Unbounded memory buffering in the HPACK parser - Unbounded CPU consumption in the HPACK parser     The unbounded CPU consumption is down to a copy that occurred per-input-block in the parser, and because     that could be unbounded due to the memory copy bug we end up with an O(n^2) parsing loop, with n selected     by the client. The unbounded memory buffering bugs: - The header size limit check was behind the string     reading code, so we needed to first buffer up to a 4 gigabyte string before rejecting it as longer than 8     or 16kb. - HPACK varints have an encoding quirk whereby an infinite number of 0's can be added at the     start of an integer. gRPC's hpack parser needed to read all of them before concluding a parse. - gRPC's     metadata overflow check was performed per frame, so that the following sequence of frames could cause     infinite buffering: HEADERS: containing a: 1 CONTINUATION: containing a: 2 CONTINUATION: containing a: 3     etc (CVE-2023-33953)

  - Lack of error handling in the TCP server in Google's gRPC starting version 1.23 on posix-compatible     platforms (ex. Linux) allows an attacker to cause a denial of service by initiating a significant number     of connections with the server. Note that gRPC C++ Python, and Ruby are affected, but gRPC Java, and Go     are NOT affected. (CVE-2023-4785)

Note that Tenable Network Security has extracted the preceding description block directly from the EulerOS security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

According to the versions of the grpc package installed, the EulerOS installation on the remote host is affected by the following vulnerabilities :

  - gRPC contains a vulnerability that allows hpack table accounting errors could lead to unwanted disconnects     between clients and servers in exceptional cases/ Three vectors were found that allow the following DOS     attacks: - Unbounded memory buffering in the HPACK parser - Unbounded CPU consumption in the HPACK parser     The unbounded CPU consumption is down to a copy that occurred per-input-block in the parser, and because     that could be unbounded due to the memory copy bug we end up with an O(n^2) parsing loop, with n selected     by the client. The unbounded memory buffering bugs: - The header size limit check was behind the string     reading code, so we needed to first buffer up to a 4 gigabyte string before rejecting it as longer than 8     or 16kb. - HPACK varints have an encoding quirk whereby an infinite number of 0's can be added at the     start of an integer. gRPC's hpack parser needed to read all of them before concluding a parse. - gRPC's     metadata overflow check was performed per frame, so that the following sequence of frames could cause     infinite buffering: HEADERS: containing a: 1 CONTINUATION: containing a: 2 CONTINUATION: containing a: 3     etc (CVE-2023-33953)

Note that Tenable Network Security has extracted the preceding description block directly from the EulerOS security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

ID	Name	Product	Family	Severity
301414	SUSE SLED15 / SLES15 Security Update : grpc (SUSE-SU-2026:0840-1)	Nessus	SuSE Local Security Checks	high
251568	Linux Distros Unpatched Vulnerability : CVE-2023-33953	Nessus	Misc.	high
238721	TencentOS Server 4: grpc (TSSA-2025:0125)	Nessus	Tencent Local Security Checks	high
421594	SCA: security update for grpc, grpcio (GHSA-496j-2rq6-j6cc)	Tenable Cloud Security	SCA Checks	high
421594	SCA: security update for grpc, grpcio (GHSA-496j-2rq6-j6cc)	Tenable Self-Hosted Container Security	SCA Checks	high
214600	Oracle Business Intelligence Enterprise Edition (OAS 7.0) (January 2025 CPU)	Nessus	Misc.	critical
212043	RHEL 9 : rhc-worker-playbook (RHSA-2024:10761)	Nessus	Red Hat Local Security Checks	critical
204231	Photon OS 5.0: Grpc PHSA-2023-5.0-0078	Nessus	PhotonOS Local Security Checks	high
190881	SUSE SLED15: abseil-cpp-devel / grpc-devel / grpc-source / libabsl2308_0_0 / etc (SUSE-SU-2024:0573-1)	Nessus	SuSE Local Security Checks	medium
188927	EulerOS 2.0 SP9 : grpc (EulerOS-SA-2023-3300)	Nessus	Huawei Local Security Checks	high
188812	EulerOS 2.0 SP9 : grpc (EulerOS-SA-2023-3332)	Nessus	Huawei Local Security Checks	high
188333	EulerOS 2.0 SP10 : grpc (EulerOS-SA-2024-1059)	Nessus	Huawei Local Security Checks	high
188254	EulerOS 2.0 SP11 : grpc (EulerOS-SA-2023-3030)	Nessus	Huawei Local Security Checks	high
188229	EulerOS 2.0 SP11 : grpc (EulerOS-SA-2023-3007)	Nessus	Huawei Local Security Checks	high
188141	EulerOS 2.0 SP10 : grpc (EulerOS-SA-2024-1083)	Nessus	Huawei Local Security Checks	high

Detections

Analytics

CVE-2023-33953

high

Tenable Plugins

high

high

high

high

high

critical

critical

high

medium

high

high

high

high

high

high