### Impact [PROXY protocol support for Puma](https://github.com/puma/puma/issues/2651) was added in version 5.5.0. When PROXY protocol v1 support is enabled, Puma reads incoming bytes into an internal buffer. It waits for "\r\n" to determine whether a PROXY v1 line is present. If an attacker opens a TCP connection and continuously sends bytes without CRLF, Puma keeps appending to this pre-parse buffer. This can cause unbounded in-process memory growth and additional CPU cost from repeatedly scanning the growing buffer for CRLF. A single, unauthenticated TCP connection can drive significant memory growth and may cause process/container OOM or degraded availability. **Only Puma servers using the following non-default config are affected:** ```ruby set_remote_address proxy_protocol: :v1 ``` ### Patches Users should upgrade to versions 7.2.1 or 8.0.2. ### Workarounds - Disable PROXY protocol v1 parsing if it is not required: ```ruby # remove/comment this: # set_remote_address proxy_protocol: :v1 ``` - Restrict direct network access to Puma listeners using PROXY protocol: - Only allow trusted load balancers/reverse proxies to connect. - Block arbitrary client TCP access with firewall/security group rules. ### Resources - [HAProxy PROXY protocol specification](https://www.haproxy.org/download/1.8/doc/proxy-protocol.txt) - [CWE-400: Uncontrolled Resource Consumption](https://cwe.mitre.org/data/definitions/400.html) - [CWE-770: Allocation of Resources Without Limits or Throttling](https://cwe.mitre.org/data/definitions/770.html) - [Puma `set_remote_address` documentation](https://github.com/puma/puma/blob/master/lib/puma/dsl.rb) - [Puma client PROXY protocol parsing code](https://github.com/puma/puma/blob/master/lib/puma/client.rb) - [Puma constants, including `PROXY_PROTOCOL_V1_REGEX`](https://github.com/puma/puma/blob/master/lib/puma/const.rb)
### Impact [PROXY protocol support for Puma](https://github.com/puma/puma/issues/2651) was added in version 5.5.0. When PROXY protocol v1 support is enabled, Puma reads incoming bytes into an internal buffer. It waits for "\r\n" to determine whether a PROXY v1 line is present. If an attacker opens a TCP connection and continuously sends bytes without CRLF, Puma keeps appending to this pre-parse buffer. This can cause unbounded in-process memory growth and additional CPU cost from repeatedly scanning the growing buffer for CRLF. A single, unauthenticated TCP connection can drive significant memory growth and may cause process/container OOM or degraded availability. **Only Puma servers using the following non-default config are affected:** ```ruby set_remote_address proxy_protocol: :v1 ``` ### Patches Users should upgrade to versions 7.2.1 or 8.0.2. ### Workarounds - Disable PROXY protocol v1 parsing if it is not required: ```ruby # remove/comment this: # set_remote_address proxy_protocol: :v1 ``` - Restrict direct network access to Puma listeners using PROXY protocol: - Only allow trusted load balancers/reverse proxies to connect. - Block arbitrary client TCP access with firewall/security group rules. ### Resources - [HAProxy PROXY protocol specification](https://www.haproxy.org/download/1.8/doc/proxy-protocol.txt) - [CWE-400: Uncontrolled Resource Consumption](https://cwe.mitre.org/data/definitions/400.html) - [CWE-770: Allocation of Resources Without Limits or Throttling](https://cwe.mitre.org/data/definitions/770.html) - [Puma `set_remote_address` documentation](https://github.com/puma/puma/blob/master/lib/puma/dsl.rb) - [Puma client PROXY protocol parsing code](https://github.com/puma/puma/blob/master/lib/puma/client.rb) - [Puma constants, including `PROXY_PROTOCOL_V1_REGEX`](https://github.com/puma/puma/blob/master/lib/puma/const.rb)
Update puma to 8.0.2; puma to 7.2.1 if you use the affected versions. Test the change in a non-production environment first.
Local check
hol-guard supply-chain scanPuma PROXY Protocol v1 Parser Allows Remote Memory Exhaustion affects puma (rubygems), puma (rubygems). Severity is high. ### Impact [PROXY protocol support for Puma](https://github.com/puma/puma/issues/2651) was added in version 5.5.0. When PROXY protocol v1 support is enabled, Puma reads incoming bytes into an internal buffer. It waits for "\r\n" to determine whether a PROXY v1 line is present. If an attacker opens a TCP connection and continuously sends bytes without CRLF, Puma keeps appending to this pre-parse buffer. This can cause unbounded in-process memory growth and additional CPU cost from repeatedly scanning the growing buffer for CRLF. A single, unauthenticated TCP connection can drive significant memory growth and may cause process/container OOM or degraded availability. **Only Puma servers using the following non-default config are affected:** ```ruby set_remote_address proxy_protocol: :v1 ``` ### Patches Users should upgrade to versions 7.2.1 or 8.0.2. ### Workarounds - Disable PROXY protocol v1 parsing if it is not required: ```ruby # remove/comment this: # set_remote_address proxy_protocol: :v1 ``` - Restrict direct network access to Puma listeners using PROXY protocol: - Only allow trusted load balancers/reverse proxies to connect. - Block arbitrary client TCP access with firewall/security group rules. ### Resources - [HAProxy PROXY protocol specification](https://www.haproxy.org/download/1.8/doc/proxy-protocol.txt) - [CWE-400: Uncontrolled Resource Consumption](https://cwe.mitre.org/data/definitions/400.html) - [CWE-770: Allocation of Resources Without Limits or Throttling](https://cwe.mitre.org/data/definitions/770.html) - [Puma `set_remote_address` documentation](https://github.com/puma/puma/blob/master/lib/puma/dsl.rb) - [Puma client PROXY protocol parsing code](https://github.com/puma/puma/blob/master/lib/puma/client.rb) - [Puma constants, including `PROXY_PROTOCOL_V1_REGEX`](https://github.com/puma/puma/blob/master/lib/puma/const.rb)
AI coding agents often install or upgrade packages automatically in rubygems. A high vulnerability in a dependency can be pulled into a project through a normal install or update without a human reviewing the change, expanding the blast radius from a single package to every agent workspace that depends on it.
| Package | Affected range | Fixed version |
|---|---|---|
| pumarubygems | >=8.0.0,<8.0.2 | 8.0.2 |
| pumarubygems | >=5.5.0,<7.2.1 | 7.2.1 |
Fixed versions are reported by the source feed; confirm compatibility before updating.
Reported by GitHub Security Advisories (ghsa).
HOL Guard can help your team review package activity against supported protection paths.
Explore HOL GuardUpdate puma to 8.0.2; puma to 7.2.1 if you use the affected versions. Test the change in a non-production environment first.
Local check
hol-guard supply-chain scanPuma PROXY Protocol v1 Parser Allows Remote Memory Exhaustion affects puma (rubygems), puma (rubygems). Severity is high. ### Impact [PROXY protocol support for Puma](https://github.com/puma/puma/issues/2651) was added in version 5.5.0. When PROXY protocol v1 support is enabled, Puma reads incoming bytes into an internal buffer. It waits for "\r\n" to determine whether a PROXY v1 line is present. If an attacker opens a TCP connection and continuously sends bytes without CRLF, Puma keeps appending to this pre-parse buffer. This can cause unbounded in-process memory growth and additional CPU cost from repeatedly scanning the growing buffer for CRLF. A single, unauthenticated TCP connection can drive significant memory growth and may cause process/container OOM or degraded availability. **Only Puma servers using the following non-default config are affected:** ```ruby set_remote_address proxy_protocol: :v1 ``` ### Patches Users should upgrade to versions 7.2.1 or 8.0.2. ### Workarounds - Disable PROXY protocol v1 parsing if it is not required: ```ruby # remove/comment this: # set_remote_address proxy_protocol: :v1 ``` - Restrict direct network access to Puma listeners using PROXY protocol: - Only allow trusted load balancers/reverse proxies to connect. - Block arbitrary client TCP access with firewall/security group rules. ### Resources - [HAProxy PROXY protocol specification](https://www.haproxy.org/download/1.8/doc/proxy-protocol.txt) - [CWE-400: Uncontrolled Resource Consumption](https://cwe.mitre.org/data/definitions/400.html) - [CWE-770: Allocation of Resources Without Limits or Throttling](https://cwe.mitre.org/data/definitions/770.html) - [Puma `set_remote_address` documentation](https://github.com/puma/puma/blob/master/lib/puma/dsl.rb) - [Puma client PROXY protocol parsing code](https://github.com/puma/puma/blob/master/lib/puma/client.rb) - [Puma constants, including `PROXY_PROTOCOL_V1_REGEX`](https://github.com/puma/puma/blob/master/lib/puma/const.rb)
AI coding agents often install or upgrade packages automatically in rubygems. A high vulnerability in a dependency can be pulled into a project through a normal install or update without a human reviewing the change, expanding the blast radius from a single package to every agent workspace that depends on it.
| Package | Affected range | Fixed version |
|---|---|---|
| pumarubygems | >=8.0.0,<8.0.2 | 8.0.2 |
| pumarubygems | >=5.5.0,<7.2.1 | 7.2.1 |
Fixed versions are reported by the source feed; confirm compatibility before updating.
Reported by GitHub Security Advisories (ghsa).
HOL Guard can help your team review package activity against supported protection paths.
Explore HOL Guard