GHSA-4j3c-42xv-3f84 BIT-tomcat-2025-52434 CVE-2025-52434
Apache Tomcat is vulnerable to resource exhaustion when using the APR/Native connector
- Severity
- 0.0 / 10
- High · CVSS 4.0
- Exploit chance (EPSS)
- 2.07%
- Chance of exploitation in the next 30 days. Higher than 81.47% of scored vulnerabilities.
- Known exploited
- No
- Not in CISA's catalog
- Weakness
- CWE-362 Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')
- Fix
- Available
- 2 packages have a fixed version
Description
Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition') vulnerability in Apache Tomcat when using the APR/Native connector. This was particularly noticeable with client initiated closes of HTTP/2 connections.
This issue affects Apache Tomcat: from 9.0.0.M1 through 9.0.106. The following versions were EOL at the time the CVE was created but are known to be affected: 8.5.0 through 8.5.100. Other, older, EOL versions may also be affected.
Users are recommended to upgrade to version 9.0.107, which fixes the issue.
Affected versions
Maven
| Package | Vulnerable | Fixed in |
|---|---|---|
| org.apache.tomcat.embed:tomcat-embed-core | >= 9.0.0.M1, < 9.0.107 |
9.0.107 |
| org.apache.tomcat.embed:tomcat-embed-core | >= 8.5.0, <= 8.5.100 |
No fix yet |
| org.apache.tomcat:tomcat-coyote | >= 9.0.0.M1, < 9.0.107 |
9.0.107 |
| org.apache.tomcat:tomcat-coyote | >= 8.5.0, <= 8.5.100 |
No fix yet |
How to fix
Move to the fixed version or later with your package manager, update the lockfile, and run your tests. If the package only arrives through another dependency, upgrade that dependency first. If none of its releases pulls a fixed version yet, force the version with your package manager's override.
org.apache.tomcat.embed:tomcat-embed-core Maven → 9.0.107
- maven
<dependency><groupId>org.apache.tomcat.embed</groupId><artifactId>tomcat-embed-core</artifactId><version>9.0.107</version></dependency>- gradle
implementation("org.apache.tomcat.embed:tomcat-embed-core:9.0.107")
org.apache.tomcat:tomcat-coyote Maven → 9.0.107
- maven
<dependency><groupId>org.apache.tomcat</groupId><artifactId>tomcat-coyote</artifactId><version>9.0.107</version></dependency>- gradle
implementation("org.apache.tomcat:tomcat-coyote:9.0.107")
Severity breakdown
CVSS 4.0 0.0
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:H/E:U
- Attack vector
- Network
- Attack complexity
- Low
- Attack requirements
- Present
- Privileges required
- None
- User interaction
- None
- Confidentiality (vulnerable system)
- None
- Integrity (vulnerable system)
- None
- Availability (vulnerable system)
- High
- Confidentiality (subsequent systems)
- None
- Integrity (subsequent systems)
- None
- Availability (subsequent systems)
- High
- Exploit maturity
- Unreported
CVSS 3.1 7.5
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- None
- Availability
- High
Weakness
CWE-362: Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')
The product contains a concurrent code sequence that requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence operating concurrently.
How to prevent it
- Architecture and Design: In languages that support it, use synchronization primitives. Only wrap these around critical code to minimize the impact on performance.
- Architecture and Design: Use thread-safe capabilities such as the data access abstraction in Spring.
- Architecture and Design: Minimize the usage of shared resources in order to remove as much complexity as possible from the control flow and to reduce the likelihood of unexpected conditions occurring. Additionally, this will minimize the amount of synchronization necessary and may even help to reduce the likelihood of a denial of service where an attacker may be able to repeatedly trigger a critical section (CWE-400).
- Implementation: When using multithreading and operating on shared variables, only use thread-safe functions.
- Implementation: Use atomic operations on shared variables. Be wary of innocent-looking constructs such as "x++". This may appear atomic at the code layer, but it is actually non-atomic at the instruction layer, since it involves a read, followed by a computation, followed by a write.
- Implementation: Use a mutex if available, but be sure to avoid related weaknesses such as CWE-412.
- Implementation: Avoid double-checked locking (CWE-609) and other implementation errors that arise when trying to avoid the overhead of synchronization.
- Implementation: Disable interrupts or signals over critical parts of the code, but also make sure that the code does not go into a large or infinite loop.
- Implementation: Use the volatile type modifier for critical variables to avoid unexpected compiler optimization or reordering. This does not necessarily solve the synchronization problem, but it can help.
- Architecture and Design, Operation: Run your code using the lowest privileges that are required to accomplish the necessary tasks [REF-76]. If possible, create isolated accounts with limited privileges that are only used for a single task. That way, a successful attack will not immediately give the attacker access to the rest of the software or its environment. For example, database applications rarely need to run as the database administrator, especially in day-to-day operations.
References
Advisories
Packages
Other links
Timeline
- Published
- Last updated by the source
- Latest EPSS score
Related advisories
| Advisory | Severity | Why it's related |
|---|---|---|
| GHSA-83qj-6fr2-vhqg Apache Tomcat: Potential RCE and/or information disclosure and/or information corruption with partial PUT | Critical Known exploited | Also affects org.apache.tomcat.embed:tomcat-embed-core |
| GHSA-qppj-fm5r-hxr3 HTTP/2 Stream Cancellation Attack | Medium Known exploited | Also affects org.apache.tomcat.embed:tomcat-embed-core |
| GHSA-xjgh-84hx-56c5 Unrestricted Upload of File with Dangerous Type Apache Tomcat | High Known exploited | Also affects org.apache.tomcat.embed:tomcat-embed-core |
| CVE-2020-1938 Improper Privilege Management in Tomcat | Critical Known exploited | Also affects org.apache.tomcat.embed:tomcat-embed-core |
| GHSA-pjfr-qf3p-3q25 When running Apache Tomcat on Windows with HTTP PUTs enabled it was possible to upload a JSP file to the server | High Known exploited | Also affects org.apache.tomcat.embed:tomcat-embed-core |
| GHSA-h3x4-894j-xpx5 Apache Tomcat's FORM authentication process has an Incorrect Authorization vulnerability | Critical | Also affects org.apache.tomcat.embed:tomcat-embed-core |
| GHSA-9xv2-5v5q-p794 Apache Tomcat's DIGEST authenticator has an Authentication Bypass by Capture-replay vulnerability | Critical | Also affects org.apache.tomcat.embed:tomcat-embed-core |
| GHSA-f525-44xv-f2qj Apache Tomcat - HTTP/2 no-authority bypass of strict SNI validation | Critical | Also affects org.apache.tomcat.embed:tomcat-embed-core |
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