LegacySocketAdapter timeouts and geckodriver errors

[Peter Browning]

Hello all,

Sorry for another discussion- It's not my intention to spam.

I am having a few issues when running my automation plan-

Firstly, the `zap.log` file is flooded with the following java stacktrace

2026-01-08 16:08:16,557 [ZAP-IO-Server-1-45] ERROR UncaughtExceptionLogger - Exception in thread "ZAP-IO-Server-1-45"

java.util.NoSuchElementException: timeout

at io.netty.channel.DefaultChannelPipeline.getContextOrDie(DefaultChannelPipeline.java:1073)

at io.netty.channel.DefaultChannelPipeline.remove(DefaultChannelPipeline.java:423)

at org.zaproxy.addon.network.internal.handlers.LegacySocketAdapter.<init>(LegacySocketAdapter.java:73)

at org.zaproxy.addon.network.internal.server.http.MainProxyHandler.postWriteResponse(MainProxyHandler.java:68)

at org.zaproxy.addon.network.internal.server.http.MainServerHandler.process(MainServerHandler.java:106)

at org.zaproxy.addon.network.internal.server.http.MainServerHandler.lambda$channelRead0$0(MainServerHandler.java:82)

at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1136)

at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:635)

at io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30)

at java.base/java.lang.Thread.run(Thread.java:840)

2026-01-08 16:08:17,652 [ZAP-IO-Server-1-15] ERROR UncaughtExceptionLogger - Exception in thread "ZAP-IO-Server-1-15"

java.util.NoSuchElementException: timeout

at io.netty.channel.DefaultChannelPipeline.getContextOrDie(DefaultChannelPipeline.java:1073)

at io.netty.channel.DefaultChannelPipeline.remove(DefaultChannelPipeline.java:423)

at org.zaproxy.addon.network.internal.handlers.LegacySocketAdapter.<init>(LegacySocketAdapter.java:73)

at org.zaproxy.addon.network.internal.server.http.MainProxyHandler.postWriteResponse(MainProxyHandler.java:68)

at org.zaproxy.addon.network.internal.server.http.MainServerHandler.process(MainServerHandler.java:106)

at org.zaproxy.addon.network.internal.server.http.MainServerHandler.lambda$channelRead0$0(MainServerHandler.java:82)

at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1136)

at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:635)

at io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30)

at java.base/java.lang.Thread.run(Thread.java:840)

which seem to be accompanied by these errors:

System info: os.name: 'Linux', os.arch: 'aarch64', os.version: '6.10.14-linuxkit', java.version: '17.0.17'

Driver info: org.openqa.selenium.firefox.FirefoxDriver

Command: [1d02be2a-6b39-4dbe-95ea-6f0075720303, getPageSource {}]

Capabilities {acceptInsecureCerts: true, browserName: firefox, browserVersion: 140.6.0, moz:accessibilityChecks: false, moz:buildID: 20251201132345, moz:geckodriverVersion: 0.36.0, moz:headless: true, moz:platformVersion: 6.10.14-linuxkit, moz:processID: 1471, moz:profile: /tmp/rust_mozprofile2kZguI, moz:shutdownTimeout: 60000, moz:webdriverClick: true, moz:windowless: false, pageLoadStrategy: normal, platformName: linux, proxy: Proxy(), setWindowRect: true, strictFileInteractability: false, timeouts: {implicit: 0, pageLoad: 300000, script: 30000}, unhandledPromptBehavior: dismiss and notify, userAgent: Mozilla/5.0 (X11; Linux x86..., webSocketUrl: ws://127.0.0.1:40005/sessio...}

Session ID: 1d02be2a-6b39-4dbe-95ea-6f0075720303

at org.openqa.selenium.remote.http.jdk.JdkHttpClient.execute(JdkHttpClient.java:423)

at org.openqa.selenium.remote.HttpCommandExecutor.execute(HttpCommandExecutor.java:212)

at org.openqa.selenium.remote.service.DriverCommandExecutor.invokeExecute(DriverCommandExecutor.java:216)

at org.openqa.selenium.remote.service.DriverCommandExecutor.execute(DriverCommandExecutor.java:174)

at org.openqa.selenium.remote.RemoteWebDriver.execute(RemoteWebDriver.java:561)

at org.openqa.selenium.remote.RemoteWebDriver.execute(RemoteWebDriver.java:638)

at org.openqa.selenium.remote.RemoteWebDriver.execute(RemoteWebDriver.java:642)

at org.openqa.selenium.remote.RemoteWebDriver.getPageSource(RemoteWebDriver.java:410)

at com.crawljax.browser.WebDriverBackedEmbeddedBrowser.getDomTreeWithFrames(WebDriverBackedEmbeddedBrowser.java:618)

at com.crawljax.browser.WebDriverBackedEmbeddedBrowser.getStrippedDom(WebDriverBackedEmbeddedBrowser.java:394)

at com.crawljax.util.ElementResolver.resolve(ElementResolver.java:55)

at com.crawljax.util.ElementResolver.resolve(ElementResolver.java:43)

at com.crawljax.core.Crawler.resolveByXpath(Crawler.java:273)

at com.crawljax.core.Crawler.fireEvent(Crawler.java:228)

at com.crawljax.core.Crawler.tryToFireEvent(Crawler.java:184)

at com.crawljax.core.Crawler.follow(Crawler.java:155)

at com.crawljax.core.Crawler.execute(Crawler.java:128)

at com.crawljax.core.CrawlTaskConsumer.handleTask(CrawlTaskConsumer.java:79)

at com.crawljax.core.CrawlTaskConsumer.pollAndHandleCrawlTasks(CrawlTaskConsumer.java:71)

at com.crawljax.core.CrawlTaskConsumer.call(CrawlTaskConsumer.java:47)

at com.crawljax.core.CrawlTaskConsumer.call(CrawlTaskConsumer.java:16)

at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264)

at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1136)

at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:635)

at java.base/java.lang.Thread.run(Thread.java:840)

Caused by: java.lang.InterruptedException

at java.base/java.util.concurrent.CompletableFuture.reportGet(CompletableFuture.java:386)

at java.base/java.util.concurrent.CompletableFuture.get(CompletableFuture.java:2073)

at org.openqa.selenium.remote.http.jdk.JdkHttpClient.execute(JdkHttpClient.java:417)

... 24 more

These two stacktraces account for roughly ~10k lines of the zap.log file.

I'm not sure what is causing this, as the stacktrace is not very helpful for a noob like me.

My second issue is that the scan is very slow, which might be attributed to the thousands of entries in the zap.log of the following:

2026-01-08 16:09:19,161 [ZAP-PassiveScan-9] WARN PassiveScanTask - Passive Scan rule Session Management Response Identified took 30 seconds to scan https://example.com application/json; charset=utf-8 12274652

2026-01-08 16:09:19,171 [ZAP-PassiveScan-13] WARN PassiveScanTask - Passive Scan rule Session Management Response Identified took 5 seconds to scan https://example.com null 0

2026-01-08 16:09:19,225 [ZAP-PassiveScan-8] WARN PassiveScanTask - Passive Scan rule Session Management Response Identified took 5 seconds to scan https://example.com null 0

2026-01-08 16:09:19,261 [ZAP-PassiveScan-7] WARN PassiveScanTask - Passive Scan rule Session Management Response Identified took 30 seconds to scan https://example.com application/json; charset=utf-8 12274652

2026-01-08 16:09:19,673 [ZAP-PassiveScan-4] WARN PassiveScanTask - Passive Scan rule Session Management Response Identified took 10 seconds to scan https://example.com application/json; charset=utf-8 17333

This may be completely intentional, but to me it seems incorrect for this scan rule to be taking up so much CPU time. Is this a common issue? 

Again, sorry for the repeated questions, and I appreciate all the help!

Best,

Peter

[thc202]

Hi,

Please provide the whole log or context for the exceptions.


Which ZAP version are you using? Those performance issues with the
Session Management Response Identified should not be happening with the
lastest version, or should be less frequent than what you are seeing.

Best regards.

[Peter Browning]

Hello!

I'm using 2.17.0, and have included the full log file.

Any insight would be much appreciated, and I'm happy to provide any additional debugging context.

Thanks again!