diff --git a/index.js b/index.js
index a0c648ea..e6bee3e2 100644
--- a/index.js
+++ b/index.js
@@ -22,6 +22,10 @@ async function run(options, plugins) {
   if (!isCi && !options.dryRun && !options.noCi) {
     logger.log('This run was not triggered in a known CI environment, running in dry-run mode.');
     options.dryRun = true;
+  } else {
+    // When running on CI, prevent the `git` CLI to prompt for username/password. See #703.
+    process.env.GIT_ASKPASS = 'echo';
+    process.env.GIT_TERMINAL_PROMPT = 0;
   }
 
   if (isCi && isPr && !options.noCi) {
diff --git a/lib/git.js b/lib/git.js
index 35f6ac8b..4a746edc 100644
--- a/lib/git.js
+++ b/lib/git.js
@@ -1,5 +1,8 @@
 const execa = require('execa');
 const debug = require('debug')('semantic-release:git');
+const envCi = require('env-ci');
+
+const timeout = envCi().isCi ? 10000 : 0;
 
 /**
  * Get the commit sha for a given tag.
@@ -10,7 +13,7 @@ const debug = require('debug')('semantic-release:git');
  */
 async function gitTagHead(tagName) {
   try {
-    return await execa.stdout('git', ['rev-list', '-1', tagName]);
+    return await execa.stdout('git', ['rev-list', '-1', tagName], {timeout});
   } catch (err) {
     debug(err);
   }
@@ -21,7 +24,7 @@ async function gitTagHead(tagName) {
  * @throws {Error} If the `git` command fails.
  */
 async function gitTags() {
-  return (await execa.stdout('git', ['tag']))
+  return (await execa.stdout('git', ['tag'], {timeout}))
     .split('\n')
     .map(tag => tag.trim())
     .filter(tag => Boolean(tag));
@@ -36,7 +39,7 @@ async function gitTags() {
  */
 async function isRefInHistory(ref) {
   try {
-    return (await execa('git', ['merge-base', '--is-ancestor', ref, 'HEAD'])).code === 0;
+    return (await execa('git', ['merge-base', '--is-ancestor', ref, 'HEAD'], {timeout})).code === 0;
   } catch (err) {
     debug(err);
   }
@@ -46,14 +49,14 @@ async function isRefInHistory(ref) {
  * Unshallow the git repository (retriving every commits and tags).
  */
 async function unshallow() {
-  await execa('git', ['fetch', '--unshallow', '--tags'], {reject: false});
+  await execa('git', ['fetch', '--unshallow', '--tags'], {reject: false, timeout});
 }
 
 /**
  * @return {string} the sha of the HEAD commit.
  */
 async function gitHead() {
-  return execa.stdout('git', ['rev-parse', 'HEAD']);
+  return execa.stdout('git', ['rev-parse', 'HEAD'], {timeout});
 }
 
 /**
@@ -61,7 +64,7 @@ async function gitHead() {
  */
 async function repoUrl() {
   try {
-    return await execa.stdout('git', ['remote', 'get-url', 'origin']);
+    return await execa.stdout('git', ['remote', 'get-url', 'origin'], {timeout});
   } catch (err) {
     debug(err);
   }
@@ -72,7 +75,7 @@ async function repoUrl() {
  */
 async function isGitRepo() {
   try {
-    return (await execa('git', ['rev-parse', '--git-dir'])).code === 0;
+    return (await execa('git', ['rev-parse', '--git-dir'], {timeout})).code === 0;
   } catch (err) {
     debug(err);
   }
@@ -88,7 +91,7 @@ async function isGitRepo() {
  */
 async function verifyAuth(origin, branch) {
   try {
-    return (await execa('git', ['push', '--dry-run', origin, `HEAD:${branch}`])).code === 0;
+    return (await execa('git', ['push', '--dry-run', origin, `HEAD:${branch}`], {timeout})).code === 0;
   } catch (err) {
     debug(err);
   }
@@ -101,7 +104,7 @@ async function verifyAuth(origin, branch) {
  * @throws {Error} if the tag creation failed.
  */
 async function tag(tagName) {
-  await execa('git', ['tag', tagName]);
+  await execa('git', ['tag', tagName], {timeout});
 }
 
 /**
@@ -112,19 +115,18 @@ async function tag(tagName) {
  * @throws {Error} if the push failed.
  */
 async function push(origin, branch) {
-  await execa('git', ['push', '--tags', origin, `HEAD:${branch}`]);
+  await execa('git', ['push', '--tags', origin, `HEAD:${branch}`], {timeout});
 }
 
 /**
  * Verify a tag name is a valid Git reference.
  *
- * @method verifyTagName
  * @param {string} tagName the tag name to verify.
  * @return {boolean} `true` if valid, falsy otherwise.
  */
 async function verifyTagName(tagName) {
   try {
-    return (await execa('git', ['check-ref-format', `refs/tags/${tagName}`])).code === 0;
+    return (await execa('git', ['check-ref-format', `refs/tags/${tagName}`], {timeout})).code === 0;
   } catch (err) {
     debug(err);
   }