Ember: Unneutralised terminal escape/control sequences from Caddy logs injected into the operator's TUI

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No collected risk observation for these identifiers. This does not establish absence of exploitation or a zero probability.

Ember is a real-time terminal dashboard for Caddy servers with FrankenPHP support. Prior to 1.4.2, interactive TUI row formatters pass Caddy access-log fields, particularly the request URI, through the `fitCellLeft` render helper without neutralizing terminal escape or control sequences. An unauthenticated remote client can place ANSI, OSC, or CSI control bytes in an ordinary HTTP request target. Caddy JSON-escapes those bytes, `ParseLogLine` decodes them back into raw controls, and the formatters concatenate them into `View()` output reaching `os.Stdout`. When the operator views the default `Logs` tab, the terminal interprets these sequences, allowing monitoring-dashboard spoofing, clipboard hijacking through `OSC 52`, and window-title spoofing through `OSC 0/2`. This works even with a loopback-only log listener because the input arrives through normal Caddy access logs. `Certificates` and `Routes` share secondary unneutralized render sinks. The `--json`, `--once`, and daemon `--expose` modes are unaffected because they do not render an interactive terminal. Consequences depend on the terminal emulator and usually require further operator action to escalate; this is not general-purpose remote code execution. This issue is fixed in version 1.4.2.

Source published

28 Oct 2026 19:44:41 UTC

Source modified

29 Oct 2026 18:31:49 UTC

Observed here

29 Oct 2026 19:28:49 UTC

Source terms

CVE Program Terms of Use

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CVSS 3.1 · 4.7 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:N/I:L/A:N

Ember is a real-time terminal dashboard for Caddy servers with FrankenPHP support. Prior to 1.4.2, interactive TUI row formatters pass Caddy access-log fields, particularly the request URI, through the `fitCellLeft` render helper without neutralizing terminal escape or control sequences. An unauthenticated remote client can place ANSI, OSC, or CSI control bytes in an ordinary HTTP request target. Caddy JSON-escapes those bytes, `ParseLogLine` decodes them back into raw controls, and the formatters concatenate them into `View()` output reaching `os.Stdout`. When the operator views the default `Logs` tab, the terminal interprets these sequences, allowing monitoring-dashboard spoofing, clipboard hijacking through `OSC 52`, and window-title spoofing through `OSC 0/2`. This works even with a loopback-only log listener because the input arrives through normal Caddy access logs. `Certificates` and `Routes` share secondary unneutralized render sinks. The `--json`, `--once`, and daemon `--expose` modes are unaffected because they do not render an interactive terminal. Consequences depend on the terminal emulator and usually require further operator action to escalate; this is not general-purpose remote code execution. This issue is fixed in version 1.4.2.

Source published

Oct 28, 2026, 7:44:41 PM (timezone not stated)

Source modified

Oct 29, 2026, 6:31:49 PM (timezone not stated)

Observed here

5 Nov 2026 11:40:49 UTC

Source terms

ENISA EUVD · source terms and attribution apply

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This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: euvd · ENISA EUVD · source terms and attribution apply. Source text is retained; field grouping and change labels are provided by ChangeIntel.

EUVD CVSS 3.1 · 4.7 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:N/I:L/A:N

Ember is a real-time terminal dashboard for Caddy servers with FrankenPHP support. Prior to 1.4.2, interactive TUI row formatters pass Caddy access-log fields, particularly the request URI, through the `fitCellLeft` render helper without neutralizing terminal escape or control sequences. An unauthenticated remote client can place ANSI, OSC, or CSI control bytes in an ordinary HTTP request target. Caddy JSON-escapes those bytes, `ParseLogLine` decodes them back into raw controls, and the formatters concatenate them into `View()` output reaching `os.Stdout`. When the operator views the default `Logs` tab, the terminal interprets these sequences, allowing monitoring-dashboard spoofing, clipboard hijacking through `OSC 52`, and window-title spoofing through `OSC 0/2`. This works even with a loopback-only log listener because the input arrives through normal Caddy access logs. `Certificates` and `Routes` share secondary unneutralized render sinks. The `--json`, `--once`, and daemon `--expose` modes are unaffected because they do not render an interactive terminal. Consequences depend on the terminal emulator and usually require further operator action to escalate; this is not general-purpose remote code execution. This issue is fixed in version 1.4.2.

Source published

28 Oct 2026 20:18:00 UTC

Source modified

29 Oct 2026 19:17:22 UTC

Observed here

31 Oct 2026 15:05:16 UTC

Source terms

NIST NVD usage terms; underlying source attribution retained

Original source record · Cite this exact observation · Complete original publisher JSON

This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: nvd · NIST NVD usage terms; underlying source attribution retained. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS 3.1 · [email protected] · Secondary · 4.7 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:N/I:L/A:N

## Summary Ember's interactive TUI renders fields taken from the monitored Caddy server's access logs — most notably the request URI — straight to the operator's terminal without neutralising terminal escape or control sequences (CWE-150). Those log fields are populated from arbitrary, unauthenticated HTTP requests, so any remote client can embed ANSI/OSC/CSI control bytes that the operator's terminal emulator interprets when the log row is displayed. The bytes survive the whole pipeline: Caddy escapes them into its JSON access log as unicode escapes, ember's `ParseLogLine` decodes them back to raw `0x1b`/`0x07` bytes, and the row formatters concatenate them into the bubbletea `View()` output with no encoding before they reach `os.Stdout`. ## Impact An **unauthenticated, remote** attacker who can send HTTP requests to the Caddy server that ember monitors can inject terminal escape sequences into the operator's TUI. The trigger is a single ordinary HTTP request with control bytes in the request target. It requires no authentication; because the payload is reflected through Caddy's normal access log, it works even when ember's log listener is bound only to loopback. When the operator views the Logs tab — ember's default, zero-config mode — the terminal emulator interprets the injected sequences. Broadly-supported, demonstrated impact includes: - **Monitoring-dashboard spoofing** — CSI cursor/erase/scroll sequences forge or hide log rows so the operator misjudges the monitored server's state. - **Clipboard hijacking (OSC 52)** — attacker-chosen text is written into the operator's system clipboard, staging a payload the operator may later paste into a shell. - **Window-title spoofing (OSC 0/2)** — to support social engineering. The impact ceiling depends on the operator's terminal emulator and usually requires a further operator action (e.g. a paste) to fully escalate; this is not general-case RCE, though specific terminal emulators have historically escalated escape sequences further. The Certificates and Routes tabs share the same unneutralised render path as secondary sinks. The `--json`/`--once` and daemon (`--expose`) modes are not affected, as they do not render to an interactive terminal. ## References - https://github.com/alexandre-daubois/ember/blob/main/internal/ui/logtable.go#L18 — the unneutralised render helper (`fitCellLeft`) and row formatters (the sink) - https://github.com/alexandre-daubois/ember/blob/main/internal/fetcher/lognetlistener.go — the unauthenticated TCP access-log listener (input source) - https://github.com/alexandre-daubois/ember/blob/main/internal/fetcher/logentry.go — `ParseLogLine`, where the JSON decode restores raw control bytes - https://cwe.mitre.org/data/definitions/150.html — CWE-150: Improper Neutralization of Escape, Meta, or Control Sequences

Source published

20 Aug 2026 18:36:01 UTC

Source modified

10 Sep 2026 03:50:54 UTC

Observed here

24 Oct 2026 13:19:41 UTC

Source terms

GitHub Advisory Database · CC-BY-4.0

Original source record · Cite this exact observation · Complete original publisher JSON

This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: osv · GitHub Advisory Database · CC-BY-4.0. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS_V3 · CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:N/I:L/A:N

Publisher rating · MODERATE

Ember has unneutralized terminal escape/control sequences from Caddy logs injected into the operator's TUI in github.com/alexandre-daubois/ember

Source published

25 Aug 2026 19:43:10 UTC

Source modified

26 Aug 2026 01:21:30 UTC

Observed here

24 Oct 2026 13:19:41 UTC

Source terms

OSV · upstream source license applies

Original source record · Cite this exact observation · Complete original publisher JSON

This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: osv · OSV · upstream source license applies. Source text is retained; field grouping and change labels are provided by ChangeIntel.